Bug #369588 --> switch thunderbird tinderboxes to cairo

r=preed

tools/tinderbox-configs/thunderbird/linux/mozconfig

@@ -19,6 +19,5 @@ ac_add_options --disable-tests
 # ac_add_options --disable-md
 ac_add_options --disable-shared
 ac_add_options --enable-static
-ac_add_options --enable-xft
-ac_add_options --disable-freetype2
-ac_add_options --enable-default-toolkit=gtk2
+ac_add_options --enable-pango
+ac_add_options --enable-default-toolkit=cairo-gtk2

tools/tinderbox-configs/thunderbird/win32/mozconfig

@@ -10,7 +10,6 @@ mk_add_options MOZ_MAKE_FLAGS=-j1
 mk_add_options MOZ_CO_MODULE="mozilla/tools/update-packaging"
 mk_add_options MOZ_PACKAGE_NSIS=1
 
-ac_add_options --enable-default-toolkit=windows
 ac_add_options --enable-update-channel=nightly
 ac_add_options --disable-debug
 ac_add_options --enable-optimize