add rounded image corners to en.json

Author: dweymouth

res/translations/en.json

@@ -260,6 +260,7 @@
     "URL": "URL",
     "Use blurred album cover for Now Playing page background": "Use blurred album cover for Now Playing page background",
     "Use legacy authentication": "Use legacy authentication",
+    "Use rounded image corners": "Use rounded image corners",
     "Use waveform seekbar": "Use waveform seekbar",
     "Username": "Username",
     "version": "version",