p/Pgsql.pm: fix version check on windows

Thx hannibal218bc who reported :

In Pgsql.pm the version of the PostgreSQL server is extrated with a regexp from
executing "version()" (line 519 in current version):

    unless ($v =~ /^PostgreSQL (\d+)\.(\d+)\.(\d+) on/);

The regex does not match the version string that is returned from a Windows
PSQL instance:

    PostgreSQL 9.2.4, compiled by Visual C++ build 1600, 64-bit

I suggest using

    unless ($v =~ /^PostgreSQL (\d+)\.(\d+)\.(\d+)\b/);

Closes: #1434
Merge branch 'fix-1434' into stable-2.0