Update buildroot to 2021.02.1 (#1312)

Signed-off-by: Stefan Agner <stefan@agner.ch>

buildroot/support/scripts/pycompile.py

@@ -30,7 +30,7 @@ def compile_one(host_path, strip_root=None, verbose=False):
     if os.path.islink(host_path) or not os.path.isfile(host_path):
         return  # only compile real files
 
-    if not re.match(r"^[_A-Za-z][_A-Za-z0-9]+\.py$",
+    if not re.match(r"^[_A-Za-z][_A-Za-z0-9]*\.py$",
                     os.path.basename(host_path)):
         return  # only compile "importable" python modules