pgsql-server: Fix strerror_r by checking return type from configure.

Log Message:
-----------
Fix strerror_r by checking return type from configure.

Modified Files:
--------------
    pgsql-server:
        configure (r1.371 -> r1.372)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/configure.diff?r1=1.371&r2=1.372)
        configure.in (r1.360 -> r1.361)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/configure.in.diff?r1=1.360&r2=1.361)
    pgsql-server/config:
        c-library.m4 (r1.25 -> r1.26)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/config/c-library.m4.diff?r1=1.25&r2=1.26)
    pgsql-server/src/include:
        pg_config.h.in (r1.76 -> r1.77)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/pg_config.h.in.diff?r1=1.76&r2=1.77)
    pgsql-server/src/port:
        thread.c (r1.20 -> r1.21)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/port/thread.c.diff?r1=1.20&r2=1.21)