Don't rewrite the NotFound error message
Don't rewrite the NotFound error message

When user updates an image with a nonexisted location, it's
expected to run into location not found exception. However,
because the error message is rewritten in v2 image update,
so user will get below wrong message:
Failed to find image <image-id> to update

This fix will remove the rewritten message, given the NotFound
message has been set at: glance/db/sqlalchemy/api.py#L159

Closes-Bug: #1265448

Change-Id: I4e5fbbe40ce0fd13e828a40a424d4fcdc66a236b

openstack/glance,darren-wang/gl,openstack/glance,akash1808/glance,scripnichenko/glance,rajalokan/glance,redhat-openstack/glance,dims/glance,stevelle/glance,akash1808/glance,wkoathp/glance,klmitch/glance,JioCloud/glance,kfwang/Glance-OVA-OVF,jumpstarter-io/glance,redhat-openstack/glance,rajalokan/glance,saeki-masaki/glance,vuntz/glance,JioCloud/glance,tanglei528/glance,jumpstarter-io/glance,paramite/glance,dims/glance,klmitch/glance,tanglei528/glance,vuntz/glance,kfwang/Glance-OVA-OVF,takeshineshiro/glance,saeki-masaki/glance,ozamiatin/glance,stevelle/glance,sigmavirus24/glance,darren-wang/gl,scripnichenko/glance,wkoathp/glance,sigmavirus24/glance,paramite/glance,openstack/glance,takeshineshiro/glance,ozamiatin/glance