Part of Bug 617906 - Turn on IPC/OOPP in Thunderbird builds; rs=bienvenu. Actually turn on IPC. Note there is no UI for plugins that crash yet, this will come later

mail/confvars.sh

@@ -50,7 +50,6 @@ MOZ_STATIC_MAIL_BUILD=1
 MOZ_COMPOSER=1
 MOZ_SAFE_BROWSING=1
 MOZ_MORK=1
-MOZ_IPC=
 MOZ_STATIC_BUILD_UNSUPPORTED=1
 MOZ_APP_COMPONENT_LIBS="mail msgsmime import xpautocomplete mailcomps $LDAP_COMPONENT"
 MOZ_APP_EXTRA_LIBS="$LDAP_LIBS"