[SMS app] Mask regex special characters in search box

Summary: QSortFilterProxyModel filters based on a regex. When the user inserts regex special characters things go bad.

Reviewers: #kde_connect, apol

Reviewed By: #kde_connect, apol

Subscribers: apol, broulik, kdeconnect

Tags: #kde_connect

Differential Revision: https://phabricator.kde.org/D14642

smsapp/qml/ConversationList.qml

@@ -58,6 +58,7 @@ Kirigami.ScrollablePage
         model: QSortFilterProxyModel {
             sortOrder: Qt.DescendingOrder
             sortRole: ConversationListModel.DateRole
+            filterCaseSensitivity: Qt.CaseInsensitive
             sourceModel: ConversationListModel {
                 deviceId: device ? device.id() : ""
             }
@@ -68,7 +69,7 @@ Kirigami.ScrollablePage
             placeholderText: i18n("Filter...")
             width: parent.width
             onTextChanged: {
-                view.model.filterRegExp = new RegExp(filter.text, "i")
+                view.model.setFilterFixedString(filter.text);
                 view.currentIndex = 0
             }
             Keys.onUpPressed: view.currentIndex = Math.max(view.currentIndex-1, 0)