do not use -w switch as it breaks modules

-w enabled warnings for all modules - even when these modules comes from the OS and are not compatible
with warnings. This is the reason to NOT use -w and instead use "use warnings".

bin/pveam

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
 use PVE::Cluster;
 use PVE::APLInfo;
 

bin/pvectl

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
 
 use PVE::Tools qw(extract_param);
 use PVE::Cluster qw(cfs_register_file cfs_read_file);

bin/pvedaemon

-#!/usr/bin/perl -T -w
+#!/usr/bin/perl -T
 
 $ENV{'PATH'} = '/sbin:/bin:/usr/sbin:/usr/bin';
 
 delete @ENV{qw(IFS CDPATH ENV BASH_ENV)};  
 
 use strict;
+use warnings;
 use Getopt::Long;
 use POSIX ":sys_wait_h";
 use Socket;

bin/pvemailforward.pl

-#!/usr/bin/perl -w -T
+#!/usr/bin/perl -T
 
 use strict;
 use warnings;

bin/pveperf

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
 use File::Sync;
 use Time::HiRes qw( usleep ualarm gettimeofday tv_interval );
 use Net::DNS::Resolver;

bin/pveproxy

-#!/usr/bin/perl -T -w
+#!/usr/bin/perl -T
 
 $ENV{'PATH'} = '/sbin:/bin:/usr/sbin:/usr/bin';
 
 delete @ENV{qw(IFS CDPATH ENV BASH_ENV)};  
 
 use strict;
+use warnings;
 use English;
 use Getopt::Long;
 use POSIX ":sys_wait_h";

bin/pvesh

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 # TODO:
 # implement persistent history ?
  
 use strict;
+use warnings;
 use Term::ReadLine;
 use File::Basename;
 use Getopt::Long;

bin/pvestatd

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
 use PVE::SafeSyslog;
 use POSIX ":sys_wait_h";
 use Fcntl ':flock';

bin/pvesubscription

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
 
 use PVE::Tools;
 use PVE::SafeSyslog;

bin/pveupgrade

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
+
 use File::stat ();
 use Getopt::Long;
 

bin/pveversion

-#!/usr/bin/perl -w
+#!/usr/bin/perl
 
 use strict;
+use warnings;
 use POSIX;
 use Getopt::Long;
 use PVE::API2::APT;