Solved a security issue

Users could create accounts named Admin, ROOT, etc.

app/utils/valid_name.py

@@ -27,7 +27,7 @@ def valid_name(name, msg=False):
 
     # Rule 2
     try:
-        normalize(name)
+        normalized_name = normalize(name)
     except ValueError:
         errors.append("cant-normalize")
 
@@ -36,7 +36,7 @@ def valid_name(name, msg=False):
         errors.append("no-letter")
 
     # Rule 4
-    if name in V5Config.FORBIDDEN_USERNAMES:
+    if normalized_name in V5Config.FORBIDDEN_USERNAMES:
         errors.append("forbidden")
 
     return True if errors == [] else errors