[gtk] meson.build: Pull in fallback for PangoFT2 only when needed

[Chun-wei Fan <fanchunwei src gnome org>]

commit 6b08227110cb61184018d2fd01d9baca6d0d0ee8
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Mar 29 16:47:31 2019 +0800

    meson.build: Pull in fallback for PangoFT2 only when needed
    
    On some systems PangoFT2 is optional, so we only use the fallback when
    it is being required.

 meson.build | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index 7319640b10..4d6201b50c 100644
--- a/meson.build
+++ b/meson.build
@@ -331,8 +331,7 @@ fribidi_dep    = dependency('fribidi', version: fribidi_req,
 
 # Require PangoFT2 if on X11 or wayland
 require_pangoft2 = wayland_enabled or x11_enabled
-pangoft_dep    = dependency('pangoft2', required: require_pangoft2,
-                            fallback : ['pango', 'libpangoft2_dep'])
+pangoft_dep    = dependency('pangoft2', required: false)
 
 if pangoft_dep.found()
   # Need at least 2.7.1 for FT_Get_Var_Design_Coordinates()
@@ -361,6 +360,10 @@ if pangoft_dep.found()
   endif
 endif
 
+if require_pangoft2
+  pangoft_dep    = dependency('pangoft2', fallback : ['pango', 'libpangoft2_dep'])
+endif
+
 if win32_enabled
   # for GTK_IM_CONTEXT_IME
   pangowin32_dep  = dependency('pangowin32')