Update to fixed mavlink and include mavlink in precompiled headers for good measure

v1.0 @ 28ea42cc

-Subproject commit b6d21f1226857ff6ad710524d2b6956687011e64
+Subproject commit 28ea42ccb6ab1d764cacf3f0f55358dc3c66faa9

qgroundcontrol.pro

@@ -783,9 +783,8 @@ SOURCES += \
     src/VideoStreaming/VideoStreaming.cc \
     src/VideoStreaming/VideoSurface.cc \
 
-contains (DEFINES, DISABLE_VIDEOSTREAMING) {
+contains (CONFIG, DISABLE_VIDEOSTREAMING) {
     message("Skipping support for video streaming (manual override from command line)")
-    DEFINES -= DISABLE_VIDEOSTREAMING
 # Otherwise the user can still disable this feature in the user_config.pri file.
 } else:exists(user_config.pri):infile(user_config.pri, DEFINES, DISABLE_VIDEOSTREAMING) {
     message("Skipping support for video streaming (manual override from user_config.pri)")