Put SR URL fetch in try so that it doesn't break slapgrid in case of problem

slapos/grid/slapgrid.py

@@ -648,6 +648,7 @@ class Slapgrid(object):
             exception = traceback.format_exc()
             logger.error(exception)
 
+      try:
         software_path = os.path.join(self.software_root,
               getSoftwareUrlHash(software_url))
         local_partition = Partition(
@@ -664,7 +665,7 @@ class Slapgrid(object):
           software_release_url=software_url,
           certificate_repository_path=self.certificate_repository_path,
           console=self.console, buildout=self.buildout)
-      try:
+
         computer_partition_state = computer_partition.getState()
         if computer_partition_state == "started":
           local_partition.install()