build: default git sha to GitNotFound in case git fails

build

@@ -11,7 +11,7 @@ ln -s ${PWD} $GOPATH/src/${REPO_PATH}
 
 eval $(go env)
 
-GIT_SHA=`git rev-parse --short HEAD`
+GIT_SHA=`git rev-parse --short HEAD || echo "GitNotFound"`
 
 # Static compilation is useful when etcd is run in a container
 CGO_ENABLED=0 go build -a -installsuffix cgo -ldflags "-s -X ${REPO_PATH}/version.GitSHA ${GIT_SHA}" -o bin/etcd ${REPO_PATH}