fix: swap the order of metadata parameters in verifying signatures on incoming...

fix: swap the order of metadata parameters in verifying signatures on incoming messages, so the correct certificate from the SP(!) metadata is used to check the signature instead of the IDP one

git-svn-id: https://simplesamlphp.googlecode.com/svn/trunk@2185 44740490-163a-0410-bde0-09ae8108e29a