Qt: Remove renderer title from top group box

Save a little vertical space.

pcsx2-qt/Settings/GraphicsSettingsWidget.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>720</width>
-    <height>492</height>
+    <height>463</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -29,7 +29,7 @@
    <item>
     <widget class="QGroupBox" name="groupBox_3">
      <property name="title">
-      <string>Renderer</string>
+      <string/>
      </property>
      <layout class="QFormLayout" name="formLayout">
       <item row="0" column="0">