Corrected 'hangup' to 'hang up' (#5930)

webapp/i18n/en.json

@@ -2367,9 +2367,9 @@
   "webrtc.declined": "Your call has been declined by {username}.",
   "webrtc.disabled": "{username} has WebRTC disabled, and cannot receive calls. To enable the feature, they must go to Account Settings > Advanced > Preview pre-release features and turn on WebRTC.",
   "webrtc.failed": "There was a problem connecting the video call.",
-  "webrtc.hangup": "Hangup",
+  "webrtc.hangup": "Hang up",
   "webrtc.header": "Call with {username}",
-  "webrtc.inProgress": "You have a call in progress. Please hangup first.",
+  "webrtc.inProgress": "You have a call in progress. Please hang up first.",
   "webrtc.mediaError": "Unable to access camera or microphone.",
   "webrtc.mute_audio": "Mute microphone",
   "webrtc.noAnswer": "{username} is not answering the call.",