g_object_unref is in form of `void (*)(gpointer)`, which matches the
GDestroyNotify signature. An explicit GDestroyNotify cast on
g_object_unref is thus not needed.
html/MMCallProperties.html:141: warning: no link for: 'mm-modem-voice-create' -> (<code class="function">mm_modem_voice_create()</code>).
html/MMCallProperties.html:141: warning: no link for: 'mm-modem-voice-create-sync' -> (<code class="function">mm_modem_voice_create_sync()</code>).
html/MMModemVoice.html:379: warning: no link for: 'mm-modem-voice-delete-finish' -> (<code class="function">mm_modem_voice_delete_finish()</code>).
html/MMModemVoice.html:380: warning: no link for: 'mm-modem-voice-delete-sync' -> (<code class="function">mm_modem_voice_delete_sync()</code>).
