comms/owfs: update to 3.2p4

owfs 3.2p4 have been released, which among other things fixes a FreeBSD
build bug.

• Update 3.2p3 -> 3.2p4
• Change from USE_GITHUB to MASTER_SITES
• Remove OWFS Python bindings, as python2.7 is no longer supported in FreeBSD and owfs python binding does not build with anything else. It is deprecated in favour for pyownet or similar (see https://github.com/owfs/owfs/issues/75 for more details)
• Remove owtraffic as it is now builtin.
• Add uthash build dependency (header-only)

PR: 248868
Approved by: maintainer
MFH: 2020Q4 (blanket: build fix)