Using `asctime` in formatter messes up timestamp encoding about picologging

[tarasko]

I made a PR that fixes the issue
#208

[tarasko]

Well, it is not an encoding issue, it is an attempt to print an uninitialized buffer here:

picologging/src/picologging/formatter.cxx

Line 101 in e648cb3

asctime = PyUnicode_FromFormat("%s,%03d", buf, logRecord->msecs);

If you're lucky it doesn't crash python, but on a bad day it can. One way to work this around is to pass datefmt argument to basicConfig.
datefmt = "%F %T"
This will activate a different path in the code that doesn't have a bug. But still it is not possible to print (milli/micro)seconds.