configure.ac tidyup after update (ccache)

We don't use TIME_WITH_SYS_TIME
Don't check for sys/time.h twice
Minimum version was 2.52 before upgrade, no need to enforce 2.71
Set it to 2.60 (same as main swig configure.ac) - new macros
introduced by autoupdate are in 2.60.
1 file changed