Fix JSON output when stdout is not a terminal

When output is redirected, colourizer is not used, so character
replacements aren't needed too.

jmbase/jmbase/support.py

@@ -170,6 +170,7 @@ def jmprint(msg, level="info"):
     if not level in jm_color_map.keys():
         raise Exception("Unsupported formatting")
 
+    if sys.stdout.isatty():
         # .colorize_message function does a .format() on the string,
         # which does not work with string-ified json; this should
         # result in output as intended: