Update libsearpc.pc.in

[cicku]

DESTDIR shouldn't be used in PKG-CONFIG file. All $(DESTDIR) variables should only be used in Makefile. If users want to install the file into special location, let them choose the prefix before configure.

And if you have dependencies with specific version requirements, it's better to write them in the pc as well.

[lins05]

First thank your for this PR!

For the DESTDIR problem, please refer to haiwen/seafile#532

The other changes looks good to me.

[cicku]

I still don't get it because the way you handle the pkgconfig is non-standard. This would increase the downstream packagers' work albeit petty.

Anyway, you can merge other parts. But don't forget to update them when you change the requirements.

Thanks.

[vitlav]

DESTDIR is still there:
prefix=(DESTDIR)@Prefix

[vitlav]

But don't forget to update them when you change the requirements
You have to use a variables like
GLIB_REQUIRED=2.26.0
from configure.ac here.
The libsearpc.pc.in file specially has .in extension to get replacements.

[killing]

Updated in #66