[gnome-calendar] build: Remove even more dead code

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

commit 6c203d55c4ab4ec3a169024fb268a02f3dec69ea
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Sat Jan 27 00:52:45 2018 -0200

    build: Remove even more dead code

 meson.build | 6 ------
 1 file changed, 6 deletions(-)
---
diff --git a/meson.build b/meson.build
index d936ad7e..4191c7be 100644
--- a/meson.build
+++ b/meson.build
@@ -89,12 +89,6 @@ common_flags = [
   '-DGWEATHER_I_KNOW_THIS_IS_UNSTABLE'
 ]
 
-test_cflags = '-Wno-sign-compare'
-
-if cc.has_argument(cflag)
-  common_flags += [cflag]
-endif
-
 if calendar_debug
   common_flags += [
     '-DG_DISABLE_CAST_CHECKS'