Fix React unescaped entities ESLint error in RelayOwnerConfig

- Replace unescaped quotes with " entities in error message text
- Resolves react/no-unescaped-entities warning

Author: Maphikza

src/components/allowed-users/components/RelayOwnerConfig/RelayOwnerConfig.tsx

@@ -196,7 +196,7 @@ export const RelayOwnerConfig: React.FC<RelayOwnerConfigProps> = ({
 
         {npubValue && !isValid && (
           <S.ErrorText>
-            Invalid NPUB format. Must start with "npub1" and be 63 characters long.
+            Invalid NPUB format. Must start with &quot;npub1&quot; and be 63 characters long.
           </S.ErrorText>
         )}
       </S.NpubSection>