build: stop non-portable use of 'echo -e'
build: stop non-portable use of 'echo -e'

Mac OS echo doesn't like '-e' so avoid using it in our Makefile.

https://bugzilla.gnome.org/show_bug.cgi?id=667659

GNOME/dconf,GNOME/dconf,GNOME/dconf,GNOME/dconf