Error with special chars encoding in request

[jusabatier]

When trying to request cadastral infos via the dedicated pan, using special chars in co-owner id (like the '+') generate an error.

As it works in the mapfishapp extension, I compare the requested URLs, and it appears that the '+' char is URL encoded in the MFapp request URL, but not in mapstore's cadastrapp extension.

The use of a raw special char appears to result in an error for the backend.