MIT License issue and Require rpm-build

Change log:

1. Added rpm-build to Requires (prevents "rpmbuild: No such file or directory").

2. Fixed egrep multi-match in license retrieval (caused problems with the MIT License case). The fix is not very elegant (a head on the egrep result) but it works. The egrep -m option doesn't work because it refers to lines. Maybe you can use that to skip the first head?

 -m NUM, --max-count=NUM
              Stop reading a file after NUM matching lines.