BUG: Properly pass OpenSSL libraries to Slicer project. Fixes #3620

Following commit r22922 which was updating the macro ExternalProjectDependency,
list passed to external projects are automatically separated by a list
separator if one of the value contain ${CMAKE_CFG_INTDIR}.

Since on the unix, none of the value in the list was having ${CMAKE_CFG_INTDIR},
the variable OPENSSL_LIBRARIES was set to /path/to/libssl.so^^/path/to/libcrypto.so
where was /path/to/libssl.so;/path/to/libcrypto.so was expected.

This commit simply removes the explicit list transformation to let
the build system take the appropriate decision.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22939 3bd1e089-480b-0410-8dfb-8563597acbee