Check ClipData null

app/src/main/java/com/hippo/ehviewer/ui/MainActivity.java

@@ -412,7 +412,7 @@ public final class MainActivity extends StageActivity
         ClipboardManager clipboard = (ClipboardManager) getSystemService(Context.CLIPBOARD_SERVICE);
             if (clipboard != null) {
                 ClipData clip = clipboard.getPrimaryClip();
-                if (clip.getItemCount() > 0) {
+                if (clip != null && clip.getItemCount() > 0) {
                     return clip.getItemAt(0).getText().toString();
                 }
             }