[libsoup] NTLM: Fix build with ntlm enabled

[Claudio Saavedra <csaavedra src gnome org>]

commit bab0db142d508e92e72970db72cbbce3c13a526a
Author: Claudio Saavedra <csaavedra igalia com>
Date:   Tue Aug 20 16:04:06 2019 +0300

    NTLM: Fix build with ntlm enabled
    
    Just realized that build with NTLM enabled was broken (!?)

 meson.build | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index c4f4c7fb..415bf4a1 100644
--- a/meson.build
+++ b/meson.build
@@ -315,7 +315,7 @@ if host_machine.system() != 'windows'
 
   if ntlm_auth.found()
     add_project_arguments('-DUSE_NTLM_AUTH=1', language : 'c')
-    add_project_arguments('-DNTLM_AUTH=' + ntlm_auth.path(), language : 'c')
+    add_project_arguments('-DNTLM_AUTH="' + ntlm_auth.path() + '"', language : 'c')
   endif
 endif