Fixing display name limit. Fixes #1421

crates/utils/src/utils.rs

@@ -110,8 +110,8 @@ pub fn is_valid_username(name: &str) -> bool {
 // Can't do a regex here, reverse lookarounds not supported
 pub fn is_valid_preferred_username(preferred_username: &str) -> bool {
   !preferred_username.starts_with('@')
-    && preferred_username.len() >= 3
-    && preferred_username.len() <= 20
+    && preferred_username.chars().count() >= 3
+    && preferred_username.chars().count() <= 20
 }
 
 pub fn is_valid_community_name(name: &str) -> bool {