barclamp_install: Do not exit when a barclamp migration fails
barclamp_install: Do not exit when a barclamp migration fails

We still want to generate the navigation, catalog, etc.

rsalevsky/crowbar,aplanas/crowbar,dirkmueller/crowbar,toabctl/crowbar,crowbar/crowbar,SUSE-Cloud/crowbar,toabctl/crowbar,crowbar/crowbar,dirkmueller/crowbar,SUSE-Cloud/crowbar,rsalevsky/crowbar,aplanas/crowbar