Add comment about making scripts executable

build.sh

@@ -97,11 +97,11 @@ chmod g-s /usr/lib/cgi-bin/mailman/*
 # Create empty dir for webroot.
 mkdir /var/empty
 
-chmod 755 /usr/local/bin/apply-forced-params
-
-chmod 755 /usr/local/bin/clean-heldmsg
-
-chmod 755 /usr/sbin/sendmail
+# Ensure that all our scripts are executable
+chmod 755 /usr/local/bin/apply-forced-params \
+          /usr/local/bin/clean-heldmsg \
+          /usr/sbin/sendmail \
+          /start.sh
 
 # Install python-mailman-api.
 (cd /tmp ; pip install \