Remove margin around qmakestep config widget.

(cherry picked from commit 53026537)

src/plugins/qt4projectmanager/qmakestep.ui

@@ -11,6 +11,9 @@
    </rect>
   </property>
   <layout class="QFormLayout" name="formLayout">
+   <property name="margin">
+    <number>0</number>
+   </property>
    <item row="0" column="0">
     <widget class="QLabel" name="label_2">
      <property name="text">