appveyor: let build system fetch submodules

appveyor.yml

@@ -43,8 +43,6 @@ build_script:
 - call C:\PX4\toolchain\scripts\setup-environment.bat x
 # safe the repopath for switching to it in cygwin bash
 - for /f %%i in ('cygpath -u %%CD%%') do set repopath=%%i
-# fetch all submodules in parallel with limited depth
-#- call bash --login -c "cd $repopath && git submodule -q update --init --recursive --jobs=10 --depth 200"
 # build the make target
 - call bash --login -c "cd $repopath && make $PX4_CONFIG"