add forgotten import compress

pio-tools/gzip-firmware.py

@@ -34,7 +34,7 @@ def map_gzip(source, target, env):
     try:
         from zopfli.gzip import compress
     except:
-        pass
+        from gzip import compress
     def bin_gzip(source, target, env):
         # create string with location and file names based on variant
         bin_file = tasmotapiolib.get_final_bin_path(env)