bug #12169 Add DirectoryIndex to Apache configuration (OskarStark)

This PR was merged into the 3.4 branch.

Discussion
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Add DirectoryIndex to Apache configuration

If you have defined "FallbackResource /app.php" without defining
a directory index, then your main page("/") will keep loading
until the request times up.

Replaces #11941

Commits
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aaf4b48 Add DirectoryIndex to Apache configuration

Author: OskarStark

setup/web_server_configuration.rst

@@ -75,6 +75,8 @@ and increase web server performance:
         ServerAlias www.domain.tld
 
         DocumentRoot /var/www/project/web
+        DirectoryIndex /app.php
+
         <Directory /var/www/project/web>
             AllowOverride None
             Order Allow,Deny