[fs2zammad] add exact filter on looked up user emails

fs2zammad

@@ -91,8 +91,8 @@ def maybe_create_zammad_user(userdata, zammad_session, attr="login", default=Non
         except:
             # The use probably exist already...
             result = list(zammad.user.search(lowercase_email))
-            if len(result) == 1:
-                user = list.pop(result)
+            if len(result) >= 1:
+                user = next(u for u in result if u.email == lowercase_email)
                 USERMAP[lowercase_email] = user
             else:
                 print(f"Could not create/fetch user {lowercase_email}")