check supported extensions for rc.autostart generation

Tools/px4airframes/srcscanner.py

@@ -16,6 +16,8 @@ class SourceScanner(object):
         extensions = tuple(parser.GetSupportedExtensions())
         for dirname, dirnames, filenames in os.walk(srcdir):
             for filename in filenames:
+                extension = os.path.splitext(filename)[1]
+                if extension in extensions:
                     path = os.path.join(dirname, filename)
                     if not self.ScanFile(path, parser):
                         return False