Fix TextViewUtils.selectLines.hasFocus() - Crash on rotate to landscape, closes #2655, by @gsantner

Author: gsantner

app/src/main/java/net/gsantner/markor/frontend/textview/TextViewUtils.java

@@ -278,6 +278,9 @@ public static void selectLines(final EditText edit, final Integer... positions)
      * @param positions: Line indices to select
      */
     public static void selectLines(final EditText edit, final List<Integer> positions) {
+        if (edit == null) {
+            return;
+        }
         if (!edit.hasFocus()) {
             edit.requestFocus();
         }