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/
subdir('libpurple')
subdir('protocols')
if ENABLE_GTK
subdir('pidgin')
else
pidgin_doc = []
endif
if enable_consoleui
subdir('finch')
else
finch_doc = []
endif
alias_target('doc', libpurple_doc, protocols_doc, pidgin_doc, finch_doc)