Added +x to balena-run fixes hzeller#2

Change-type: patch
Signed-off-by: Chris Crocker-White <chriscw@balena.io>

Author: chrisys

Dockerfile.template

@@ -16,4 +16,6 @@ COPY src ./src
 COPY balena-run.sh ./
 COPY config.sample.json ./
 
+RUN chmod +x balena-run.sh
+
 CMD ./balena-run.sh