Handle 403 errors the same as not found

There is no reason to retry since 403 error is most likely not temporarily,
so the editor connection can be closed whenever this happens.

Signed-off-by: Julius Härtl <jus@bitgrid.net>

Author: juliusknorr

src/services/PollingBackend.js

@@ -157,7 +157,7 @@ class PollingBackend {
 					outsideChange: e.response.data.outsideChange,
 				})
 			} else if (e.response.status === 403) {
-				this._authority.emit('error', ERROR_TYPE.CONNECTION_FAILED, {})
+				this._authority.emit('error', ERROR_TYPE.SOURCE_NOT_FOUND, {})
 			} else if (e.response.status === 404) {
 				this._authority.emit('error', ERROR_TYPE.SOURCE_NOT_FOUND, {})
 			} else if (e.response.status === 503) {