Fix input field not disabled while a comment is being sent

Since the change of the text area to a content editable div the input
field was no longer disabled while a new comment was being sent. It was
caused by still trying to disable the div using the "disabled" property,
which works only on real input fields; when using a content editable div
the way to disable it is by setting "contenteditable" to "false".

Signed-off-by: Daniel Calviño Sánchez <danxuliu@gmail.com>

apps/comments/js/commentstabview.js

@@ -320,7 +320,7 @@
 				this.$container.append($comment);
 			}
 			this._postRenderItem($comment);
-			$('#commentsTabView').find('.newCommentForm div.message').text('').prop('disabled', false);
+			$('#commentsTabView').find('.newCommentForm div.message').text('').prop('contenteditable', true);
 
 			// we need to update the model, because it consists of client data
 			// only, but the server might add meta data, e.g. about mentions
@@ -620,7 +620,7 @@
 				return;
 			}
 
-			$commentField.prop('disabled', true);
+			$commentField.prop('contenteditable', false);
 			$submit.addClass('hidden');
 			$loading.removeClass('hidden');
 
@@ -673,7 +673,7 @@
 		_onSubmitError: function($form, commentId) {
 			$form.find('.submit').removeClass('hidden');
 			$form.find('.submitLoading').addClass('hidden');
-			$form.find('.message').prop('disabled', false);
+			$form.find('.message').prop('contenteditable', true);
 
 			if(!_.isUndefined(commentId)) {
 				OC.Notification.show(t('comments', 'Error occurred while updating comment with id {id}', {id: commentId}), {type: 'error'});