file.py strip preceding and trailing spaces from id strings

At.js will add a trailing space to input after inserting the completed
text. It also makes sense from a rousbtness standpoint, should a user
accidentally add any preceding or trailing whitespace, the controller
will not fail.

server/web2py/applications/vidjil/controllers/file.py

@@ -17,7 +17,7 @@ if request.env.http_origin:
 
 def extract_id(target, error):
     try:
-        id = int(target.split('(')[-1][:-1])
+        id = int(target.strip().split('(')[-1][:-1])
         return id
     except:
         raise ValueError('invalid input %s' % target)