print/qpdfview: Update to 0.4.18.b1

While here,

• Make portlint happy
• Some make options cleanup
• Remove Qt4 conditional deprecation as Qt4 support has already been dropped at r487596

PR: 233352
Submitted by: Marco Beishuizen <mbeis@xs4all.nl> (maintainer)

		Lorenzo Salvadore <phascolarctos@protonmail.ch> (initial version)