[gtk] build: Make script interpreter optional

[Benjamin Otte <otte src gnome org>]

commit 22e078580278c5403c80f9ed6b25de2d891cde5c
Author: Benjamin Otte <otte redhat com>
Date:   Thu May 30 18:34:51 2019 +0200

    build: Make script interpreter optional
    
    Running the tests needs it though, so it's only optional without tests.

 meson.build | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index 3ea4ac57d2..2de01fac9c 100644
--- a/meson.build
+++ b/meson.build
@@ -461,7 +461,8 @@ if cc.get_id() == 'msvc'
   endif
 endif
 
-cairo_csi_dep = cc.find_library('cairo-script-interpreter')
+cairo_csi_dep = cc.find_library('cairo-script-interpreter',
+                                required: get_option('build-tests'))
 
 if not harfbuzz_dep.found()
   harfbuzz_dep = dependency('harfbuzz', version: '>= 0.9', required: false,