rgw: Exceptions should be caught by const reference

/Not/ by value.

Signed-off-by: Adam C. Emerson <aemerson@redhat.com>
(cherry picked from commit 1065d7996e359283f0f3e3804cdb77b4829a9191)

diff --git a/src/rgw/rgw_acl_swift.cc b/src/rgw/rgw_acl_swift.cc
index de489444852d506640ffde5c268543722f433d66..18a999127470152793b222e12b1fc9239218feab 100644 (file)
--- a/src/rgw/rgw_acl_swift.cc
+++ b/src/rgw/rgw_acl_swift.cc
@@ -106,7 +106,7 @@ static boost::optional<ACLGrant> referrer_to_grant(std::string url_spec,
 
     grant.set_referer(url_spec, is_negative ? 0 : perm);
     return grant;
-  } catch (std::out_of_range) {
+  } catch (const std::out_of_range&) {
     return boost::none;
   }
 }