fix perl_curl_multi_delete for GlobalDestruction

[kni]

Hello.
This is the fix to prevent segmentation fault, when GlobalDestruction worked

Program terminated with signal SIGSEGV, Segmentation fault.
(gdb) bt
#0 0x081042f1 in Perl_sv_bless ()
#1 0xf70caa75 in cb_multi_socket (easy_handle=0x999a768, s=20, what=4, userptr=0x996e038, socketp=0x0) at curl-Multi-c.inc:93
#2 0xf7065f31 in Curl_multi_closed (conn=0x99d62c8, s=20) at multi.c:2433
#3 0xf7062a23 in Curl_closesocket (conn=0x99d62c8, sock=20) at connect.c:1294
#4 0xf704f9f5 in conn_free (conn=0x9468d60) at url.c:2763
#5 0xf70527f0 in Curl_disconnect (conn=0x99d62c8, dead_connection=true) at url.c:2864
#6 0xf706488c in multi_done (connp=0x9468d60, connp@entry=0x999a770, status=CURLE_OK, premature=true) at multi.c:616
#7 0xf70668f1 in curl_multi_remove_handle (multi=0x996a630, data=0x999a768) at multi.c:717
#8 0xf70cbd95 in perl_curl_multi_delete (multi=, my_perl=) at curl-Multi-c.inc:57
#9 perl_curl_multi_magic_free (my_perl=0x8a19008, sv=0x95a5b34, mg=0x9468d60) at curl-Multi-c.inc:134

[creaktive]

Thanks, check for Net::Curl v0.38 on your nearest CPAN mirror :)