pidgin/pidgin

Fix a crash in the wincred providered when adding a password.

Something about the way the freeing works on Windows causes a segfault if we memset the memory to 0 first.

Testing Done:
Created a new account, stored the password, verified it was in the Credential Manager and that Pidgin didn't crash.

Reviewed at https://reviews.imfreedom.org/r/622/
if ENABLE_DOC
subdir('reference')
endif
if ENABLE_GTK
pidgin_man = configure_file(
input : 'pidgin3.1.in',
output : 'pidgin3.1',
configuration : man_conf,
install : true,
install_dir : get_option('mandir') / 'man1')
endif
if enable_consoleui
finch_man = configure_file(
input : 'finch3.1.in',
output : 'finch3.1',
configuration : man_conf,
install : true,
install_dir : get_option('mandir') / 'man1')
endif