COMP: Fix build error occurring when OpenSSL support is disabled

While commit r22220 added SSL support ensuring the CMake option
"Slicer_USE_PYTHONQT_WITH_OPENSSL" was disabled by default. Not all OpenSSL
related code was properly excluded, this commit ensures Slicer can be
compiled with OpenSSL support disabled.

Discussion: http://slicer-devel.65872.n3.nabble.com/Windows-build-fails-due-to-missing-QSslSocket-class-tt4029446.html

See issue #2998 and #2355

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22226 3bd1e089-480b-0410-8dfb-8563597acbee
COMP: Fix unused variable warning in qMRMLSliderWidget

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22227 3bd1e089-480b-0410-8dfb-8563597acbee