Fix empty branch name

install/install-openappstack.sh

@@ -8,7 +8,11 @@ flux install \
   --namespace=flux-system
 
 # get current git branch name
-branch=$(git branch --show-current) 2>/dev/null || branch=master
+branch=$(git branch --show-current) 2>/dev/null || /bin/true
+if [ -z "$branch" ]
+then
+  branch=master
+fi
 echo "Tracking branch $branch for https://open.greenhost.net/openappstack/openappstack flux repo"
 
 flux create source git openappstack \