opusfile-0.6

Remove dependency on libcompat that was introduced on the
original configure.ac since the latest updates, because it
was reported that linkage against /usr/lib/libcompat.a may
cause trouble when the system was too old 10-CURRENT (though
the report was received 1 year ago, and it does not hurt on
the recent revision of 10-STABLE).

|  /usr/bin/ld: /usr/lib/libcompat.a(ftime.o): relocation
|  R_X86_64_PC32 against `gettimeofday@@FBSD_1.0' can not
|  be used when making a shared object; recompile with -fPIC
|  /usr/bin/ld: final link failed: Bad value