Provide an informative error message when account size limit is reached

resources/assets/js/components/ComposeModal.vue

@@ -1204,6 +1204,13 @@ export default {
 					}, 300);
 				}).catch(function(e) {
 					switch(e.response.status) {
+						case 403:
+							self.uploading = false;
+							io.value = null;
+							swal('Account size limit reached', 'Contact your admin for assistance.', 'error');
+							self.page = 2;
+						break;
+
 						case 413:
 							self.uploading = false;
 							io.value = null;