Turn warnings back on, silence warnings we can't fix

QGCCommon.pri

@@ -250,7 +250,8 @@ WindowsBuild {
         /wd4996 \   # silence warnings about deprecated strcpy and whatnot, these come from the shapefile code with is external
         /wd4005 \   # silence warnings about macro redefinition, these come from the shapefile code with is external
         /wd4290 \   # ignore exception specifications
-        /wd4267     # silence conversion from 'size_t' to 'int', possible loss of data, these come from gps drivers shared with px4
+        /wd4267 \   # silence conversion from 'size_t' to 'int', possible loss of data, these come from gps drivers shared with px4
+        /wd4100     # gst-plugins-good has this error
     WarningsAsErrorsOn {
         QMAKE_CXXFLAGS_WARN_ON += /WX
     }

qmlglsink.pri

@@ -1,6 +1,3 @@
-# FIXME: will be fixed after converting qmlglsink into .pro#static lib
-QMAKE_CXXFLAGS_WARN_ON =
-
 LinuxBuild {
     DEFINES += HAVE_QT_X11 HAVE_QT_EGLFS HAVE_QT_WAYLAND
 } else:MacBuild {

src/MissionManager/SimpleMissionItem.cc

@@ -1008,8 +1008,8 @@ double SimpleMissionItem::amslEntryAlt(void) const
         return _missionItem.param7();
     case QGroundControlQmlGlobal::AltitudeModeRelative:
         return _missionItem.param7() + _masterController->missionController()->plannedHomePosition().altitude();
-    case QGroundControlQmlGlobal::AltitudeModeNone:
-        qWarning() << "Internal Error SimpleMissionItem::amslEntryAlt: Invalid altitudeMode == AltitudeModeNone";
-        return qQNaN();
     }
+
+    qWarning() << "Internal Error SimpleMissionItem::amslEntryAlt: Invalid altitudeMode:" << _altitudeMode;
+    return qQNaN();
 }