meson: get rid of topdir_includes variable

meson.build

@@ -27,7 +27,5 @@ project('call', 'c',
 )
 
 
-topdir_includes = include_directories('.')
-
 subdir('libgdbofono')
 subdir('src')

src/meson.build

@@ -69,4 +69,4 @@ calls_resources = gnome.compile_resources(
 executable('calls', sources, enum_sources, calls_resources,
            dependencies : deps,
            link_with : gdbofono_lib,
-           include_directories : topdir_includes)
+           include_directories : include_directories('..'))