Qt Quick Desiger: fix button label capitalization

Use book-style capitalization for buttons.

Change-Id: I5e679ab7dcfa8a687da312ea7382edc5949c5c99
Reviewed-by: Marco Bubke <marco.bubke@digia.com>

src/plugins/qmldesigner/designercore/instances/puppetbuildprogressdialog.ui

@@ -49,7 +49,7 @@
      <item>
       <widget class="QPushButton" name="useFallbackPuppetPushButton">
        <property name="text">
-        <string>Use fallback QML emulation layer</string>
+        <string>Use Fallback QML Emulation Layer</string>
        </property>
        <property name="autoDefault">
         <bool>false</bool>