[epiphany] Give up on building with -Werror=format-security

[Michael Catanzaro <mcatanzaro src gnome org>]

commit d1100a27341c460dc3d574db3ae71a4e441a1c18
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Fri Sep 20 13:13:30 2019 -0500

    Give up on building with -Werror=format-security
    
    It doesn't work due to https://github.com/mesonbuild/meson/issues/5790
    so stop pretending that it does.

 meson.build | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/meson.build b/meson.build
index e31954fd3..118176fc3 100644
--- a/meson.build
+++ b/meson.build
@@ -119,7 +119,6 @@ gmp_dep = cc.find_library('gmp')
 m_dep = cc.find_library('m', required: false)
 
 cflags = cc.get_supported_arguments(['-Werror=declaration-after-statement',
-                                     '-Werror=format-security',
                                      '-Werror=implicit-function-declaration',
                                      '-Wno-cast-function-type',
                                      '-Wno-missing-field-initializers',