Fixing nagios library static path issue

This should solve the problem where the nagios library path needs to be set manually. 

Before:

    # /pub/icinga/libexec/check_nginx_status.pl -H xxx.xxx.xxx.xxx
    Can't locate utils.pm in @INC (@INC contains: /usr/local/nagios/libexec /etc/perl /usr/local/lib/perl/5.14.2 /usr/local/share/perl/5.14.2 /usr/lib/perl5 /usr/share/perl5 /usr/lib/perl/5.14 /usr/share/perl/5.14 /usr/local/lib/site_perl .) at /pub/icinga/libexec/check_nginx_status.pl line 19.
BEGIN failed--compilation aborted at /pub/icinga/libexec/check_nginx_status.pl line 19.

After patch:

    # /pub/icinga/libexec/check_nginx_status.pl -H xxx.xxx.xxx.xxx
    NGINX OK -  0.034 sec. response time, Active: 5 (Writing: 1 Reading: 0 Waiting: 4) ReqPerSec: 0.203 ConnPerSec: 0.124 ReqPerConn: 1.479|Writing=1;Reading=0;Waiting=4;Active=5;ReqPerSec=0.202614;ConnPerSec=0.124183;ReqPerConn=1.478712