Merge r1799341 from trunk:

* The libnghttp2.pc might be found in lib64 on 64 bit systems
Submitted by: rpluem
Reviewed by: rpluem, icing, ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1812393 13f79535-47bb-0310-9956-ffa450edef68