fix: overflow and empty popup (#4973)

* fixing a popup bug and wallet overflow

src/components/Popups/PopupItem.tsx

@@ -81,11 +81,11 @@ export default function PopupItem({
     popupContent = <FailedNetworkSwitchPopup chainId={content.failedSwitchNetwork} />
   }
 
-  return (
+  return popupContent ? (
     <Popup>
       <StyledClose color={theme.deprecated_text2} onClick={removeThisPopup} />
       {popupContent}
       {removeAfterMs !== null ? <AnimatedFader style={faderStyle} /> : null}
     </Popup>
-  )
+  ) : null
 }

src/components/WalletDropdown/SlideOutMenu.tsx

@@ -6,6 +6,7 @@ const Menu = styled.div`
   height: 100%;
   font-size: 16px;
   overflow: auto;
+  max-height: 450px;
 
   // Firefox scrollbar styling
   scrollbar-width: thin;