COMP: Disable OpenSSL parallel build

Commit r22220 enabled SSL support and also included a patch allowing
OpenSSL to be built in parallel. Parallel build prevent the library
from being built on MacOSX factory. Waiting this is fixed and in order
to restore the nightly build, the build is forced to be sequential.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22224 3bd1e089-480b-0410-8dfb-8563597acbee