packaging: pull gcc-c++ as a build require
packaging: pull gcc-c++ as a build require

This is needed by the sassc gem.

Signed-off-by: Miquel Sabaté Solà <b4d70704b9e7df580cab34510621dbd0aacb2dfd@suse.com>

SUSE/Portus,mssola/Portus,SUSE/Portus,mssola/Portus,mssola/Portus,SUSE/Portus,SUSE/Portus,mssola/Portus