Qt: Hide software filter box.

May remove this in the future because it's unneeded with shaders.

qt/src/DisplayPanel.cpp

@@ -98,6 +98,8 @@ DisplayPanel::DisplayPanel(EmuApplication *app_)
         if (recreate)
             app->window->recreateUIAssets();
     });
+
+    groupBox_software_filters->hide();
 }
 
 DisplayPanel::~DisplayPanel()

qt/src/DisplayPanel.ui

@@ -311,7 +311,7 @@ Output directly will cause the screen to change between the two modes and look w
     </widget>
    </item>
    <item>
-    <widget class="QGroupBox" name="groupBox_3">
+    <widget class="QGroupBox" name="groupBox_software_filters">
      <property name="title">
       <string>Software Filters</string>
      </property>