python3 strftime does not work properly in Alpine linux
In alpine3.6 linux build strftime still returns an empty string whenever `dash` is used in the format section.
Ubuntu using docker image alpine:3.6 with python3.6
<code class="python">
Python 3.6.6 (default, Aug 22 2018, 20:53:29)
[GCC 6.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from datetime import datetime
>>> now = datetime.now()
>>> format = '%B %-d, %Y, %-I:%M %p'
>>> now.strftime(format)
''
>>>
</code>
Ubuntu using docker image alpine:3.6 with python2.7
<code class="python">
Python 2.7.15 (default, Aug 22 2018, 21:15:48)
[GCC 6.3.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from datetime import datetime
>>> now = datetime.now()
>>> format = '%B %-d, %Y, %-I:%M %p'
>>> now.strftime(format)
'August 31, 2018, 11:03 AM'
>>>
</code>
(from redmine: issue id 9368, created on 2018-08-31, closed on 2018-09-11)