Debug output appears to indicate default executor even when default isn't used

[dg1727]

The user's program can run the following line to enable debug output on stderr/stdout:

logging.basicConfig(level=logging.DEBUG)

The debug output states the following message, apparently unconditionally, when user code runs .run_in_executor():

DEBUG:quamash.QEventLoop:Using default executor

... and the source code seems to confirm this [init.py starting at line 480, run_in_executor() method].

Hopefully the logic can be updated to print the mentioned message only when the default executor is being used.

[harvimt]

That's a weird error.

I don't think we expected anyone to use the debugging info unless they were actually working on the project.

[harvimt]

This fix will be released in version 0.6 when it is released.