Check for .htaccess restrictions in web installer

[RobinMcCorkell]

As reported in owncloud/core#6754:

I tried to install Owncloud 6 on a shared Host. After installing Owncloud I only get a Server Error. I tryed many but was not able to detect the error. I had to contact my Hoster. He was able to tell me that my .htaccess contains not allowed entries. After Disabling the following I get a working Owncloud. # php_value upload_max_filesize 513M # php_value post_max_size 513M # php_value memory_limit 512M # php_value mbstring.func_overload 0 # Options -Indexes

The OP wasn't expecting a way to automatically fix this, but just some way to notify the user if the htaccess is restricted in some way.