File use_system_qwt.patch of Package qgroundcontrol

Index: qgroundcontrol-3.3.0/QGCExternalLibs.pri
===================================================================
--- qgroundcontrol-3.3.0.orig/QGCExternalLibs.pri
+++ qgroundcontrol-3.3.0/QGCExternalLibs.pri
@@ -75,9 +75,7 @@ DEFINES += NOMINMAX
 # [REQUIRED] QWT plotting library dependency. Provides plotting capabilities.
 #
 !MobileBuild {
-include(libs/qwt.pri)
-DEPENDPATH += libs/qwt
-INCLUDEPATH += libs/qwt
+PKGCONFIG += Qt5Qwt6
 }
 
 #
@@ -93,7 +91,7 @@ MacBuild {
         -F$$BASEDIR/libs/lib/Frameworks \
         -framework SDL2
 } else:LinuxBuild {
-    PKGCONFIG = sdl2
+    PKGCONFIG += sdl2
 } else:WindowsBuild {
     INCLUDEPATH += $$BASEDIR/libs/lib/sdl2/msvc/include