Adding else blocks have fallback values for all variables defined with a conditions

All the fallback values equal to the default behavior as i they didn't provided
Just add them to clear as per @fabiocaccamo comments/changes request
'All variables defined with a condition should have a fallback value set in the else block of the condition.'
- https://github.com/fabiocaccamo/django-admin-interface/pull/157#discussion_r816795944
- https://github.com/fabiocaccamo/django-admin-interface/pull/157#discussion_r816796366
- https://github.com/fabiocaccamo/django-admin-interface/pull/157#discussion_r816796445
- https://github.com/fabiocaccamo/django-admin-interface/pull/157#discussion_r816796563
- https://github.com/fabiocaccamo/django-admin-interface/pull/157#discussion_r816796657

- remove --admin-interface-border-radius-0px and submit its value direct as it 0px in both if and else cases

admin_interface/static/admin_interface/css/admin-interface.css

@@ -223,8 +223,8 @@
 
 .admin-interface .selector .selector-available h2,
 .admin-interface .selector .selector-chosen h2 {
-    border-bottom-left-radius: var(--admin-interface-border-radius-0px);
+    border-bottom-left-radius: 0px;
-    border-bottom-right-radius: var(--admin-interface-border-radius-0px);
+    border-bottom-right-radius: 0px;
 }
 
 .admin-interface .selector a.selector-chooseall:focus,
@@ -379,8 +379,8 @@
 }
 
 .admin-interface .inline-group h2 {
-    border-bottom-left-radius: var(--admin-interface-border-radius-0px);
+    border-bottom-left-radius: 0px;
-    border-bottom-right-radius: var(--admin-interface-border-radius-0px);
+    border-bottom-right-radius: 0px;
 }
 
 .admin-interface .module.collapse.collapsed h2 {

admin_interface/templates/admin/base_site.html

@@ -39,6 +39,8 @@
 
         {% if theme.css_header_background_color != theme.css_module_background_color %}
             --admin-interface-main-border-top: 10px solid var(--admin-interface-module-background-color);
+        {% else %}
+            --admin-interface-main-border-top: 0px;
         {% endif %}
 
         {% if theme.logo_max_width > 0 %}
@@ -49,21 +51,30 @@
 
         {% if theme.logo_max_height > 0 %}
             --admin-interface-log-max-height: {{ theme.logo_max_height }}px;
+        {% else %}
+            --admin-interface-log-max-height: unset;
         {% endif %}
 
         {% if theme.related_modal_rounded_corners %}
             --admin-interface-related-modal-border-radius: 4px;
+        {% else %}
+            --admin-interface-related-modal-border-radius: 0px;
         {% endif %}
 
         {% if theme.css_module_rounded_corners %}
             --admin-interface-module-border-radius: 4px;
-            --admin-interface-border-radius-0px: 0px;
             --admin-interface-jsoneditor-border-radius: var(--admin-interface-module-border-radius);
             --admin-interface-jsoneditor-overflow: hidden;
+        {% else %}
+            --admin-interface-module-border-radius: 0px;
+            --admin-interface-jsoneditor-border-radius: var(--admin-interface-module-border-radius);
+            --admin-interface-jsoneditor-overflow: unset;
         {% endif %}
 
         {% if not theme.related_modal_close_button_visible %}
             --admin-interface-related-modal-close-button-display: none;
+        {% else %}
+            --admin-interface-related-modal-close-button-display: unset;
         {% endif %}
         }
     </style>