Squish: Update tst_qml_editor for fixed editor

In 3.5, the QML editor showed two empty lines at the end of
the file. Now it's only one line so only one must be unmarked.

Change-Id: I831002e5ab9d14570d2a788010806c0b3de5614c
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>

tests/system/suite_editors/tst_qml_indent/test.py

@@ -61,9 +61,8 @@ def prepareQmlFile():
             markText(editor, "End")
         else:
             markText(editor, "Ctrl+End")
-        # unmark the 2 last lines
-        for _ in range(2):
-            type(editor, "<Shift+Up>")
+        # unmark the closing brace
+        type(editor, "<Shift+Up>")
         type(editor, "<Ctrl+c>")
         for j in range(10):
             type(editor, "<Ctrl+v>")