editorconfig: Fix meson style

The syntax was wrong, resulting in it not working at all.

Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
diff --git a/.editorconfig b/.editorconfig
index c2b772d..db1f4a9 100644
--- a/.editorconfig
+++ b/.editorconfig
@@ -35,6 +35,6 @@
 [*.patch]
 trim_trailing_whitespace = false
 
-[meson.build,meson_options.txt]
+[{meson.build,meson_options.txt}]
 indent_style = space
 indent_size = 2