owncloud: Fix crash in _cleanPath with URIs with no path
owncloud: Fix crash in _cleanPath with URIs with no path

Calling _cleanPath() with an URI with no path (eg
owncloud://owncloud.example.com) would result in a crash in
_cleanPath().

This was fixed in 2d6514b5 but part of the fix was silently lost in
3de8a78e during refactoring.

Reviewed-by: Andreas Schneider <5be00ddc76278cf6077f5047ca3384a88460c671@cryptomilk.org>

meeh420/csync,meeh420/csync,meeh420/csync