pcp-update pmdapostfix install fix

[Lukas Berk <lberk@xxxxxxxxxx>]

Hi,

Please see lberk/dev on sourceware.org/git/pcpfans.git for a quick patch
for pmdapostfix.  The pmda installation was failing on RHEL6 due to the
inability to set the gid properly.

commit 17c48454790627e5a9ad2ff4273d94f026e16c20
Author: Lukas Berk <lberk@xxxxxxxxxx>
Date:   Tue Apr 28 09:58:56 2015 -0400

    Force restart for postfix pmda installation
    
    The postfix pmda requires being installed by root to change the gid
    to postfix.  Switch the required option in the Install script.

diff --git a/src/pmdas/postfix/Install b/src/pmdas/postfix/Install
index 07fe957..2ab4d19 100644
--- a/src/pmdas/postfix/Install
+++ b/src/pmdas/postfix/Install
@@ -21,7 +21,7 @@
 iam=postfix
 perl_opt=true
 daemon_opt=false
-forced_restart=false
+forced_restart=true
 
 which qshape >/dev/null 2>&1
 if test $? -ne 0; then