Remove useless check for svn phonon.

GIT_SILENT Phonon hasn't been in SVN for awhile, remove a check that
altered its module name to be correct for even older SVN.

kdesrc-build

@@ -1660,13 +1660,6 @@ sub svn_module_url
             return handle_branch_tag_option($module, 'branches');
         }
 
-        # This isn't true nowadays, but *is* true for older versions of phonon which
-        # were developed in subversion.
-        if($module eq 'phonon')
-        {
-            $module = 'kdesupport/phonon';
-        }
-
         # We can't use get_option($module) after this if we have to trim the module
         # name.
         $module = moduleBaseName($module);