don't display the name input box for public groups as they can't be modified atm

ts/components/conversation/UpdateGroupNameDialog.tsx

@@ -99,6 +99,8 @@ export class UpdateGroupNameDialog extends React.Component<Props, State> {
         {this.renderAvatar()}
         <SpacerMD />
 
+        {isAdmin ? (
+          <>
             <input
               type="text"
               className="profile-name-input"
@@ -109,8 +111,9 @@ export class UpdateGroupNameDialog extends React.Component<Props, State> {
               required={true}
               aria-required={true}
               autoFocus={true}
-          disabled={!isAdmin}
             />
+          </>
+        ) : null}
 
         <div className="session-modal__button-group">
           <SessionButton text={cancelText} onClick={this.closeDialog} />