when searching, survive errors for multiple registries

when searching multiple registries for images, if we get an error on one
of the searches, we should keep going and complete the search.  if there
is only one search registry however, we will return an error.

Resolves: #1255

Signed-off-by: baude <bbaude@redhat.com>

Closes: #1257
Approved by: mheon

pkg/varlinkapi/images.go

@@ -367,6 +367,12 @@ func (i *LibpodAPI) SearchImage(call iopodman.VarlinkCall, name string, limit in
 	for _, reg := range registries {
 		results, err := docker.SearchRegistry(getContext(), sc, reg, name, int(limit))
 		if err != nil {
+			// If we are searching multiple registries, don't make something like an
+			// auth error fatal. Unfortunately we cannot differentiate between auth
+			// errors and other possibles errors
+			if len(registries) > 1 {
+				continue
+			}
 			return call.ReplyErrorOccurred(err.Error())
 		}
 		for _, result := range results {