Adds git submodule sync in case URLs change

jetpack/addon-sdk

@@ -1 +1 @@
-Subproject commit df8823863a9c7b87eaaca3f6e384fdacd143b33b
+Subproject commit 5a73e756c5c3dd8ac9609b915534c62402a31c44

scripts/build.sh

@@ -25,6 +25,7 @@ source $VENV/bin/activate
 
 pip install -q -r requirements.txt
 
+git submodule sync -q
 git submodule update --init
 
 export SPIDERMONKEY_INSTALLATION="/usr/local/bin/tracemonkey"