pidgin/pidgin

Fix a few issues with the CredentialProvider code that snuck past review

Testing Done:
Compiled and ran unit tests locally. Verified the warnings were gone from the unit test build and verified the warning was gone from the Purple-3.0.gir build.

Reviewed at https://reviews.imfreedom.org/r/168/
PROGS = [
'account_option',
'attention_type',
'circular_buffer',
'credential_provider',
'image',
'keyvaluepair',
'protocol_action',
'protocol_attention',
'protocol_xfer',
'queued_output_stream',
'smiley',
'smiley_list',
'trie',
'util',
'xmlnode'
]
test_ui = static_library(
'test-ui',
'test_ui.c',
'test_ui.h',
c_args: [
'-DTEST_DATA_DIR="@0@/data"'.format(meson.current_source_dir())
],
dependencies: [libpurple_dep, glib]
)
foreach prog : PROGS
e = executable('test_' + prog, 'test_@0@.c'.format(prog),
c_args : [
'-DTEST_DATA_DIR="@0@/data"'.format(meson.current_source_dir())
],
dependencies : [libpurple_dep, glib],
link_with: test_ui,
)
test(prog, e)
endforeach