CI: Attempt to mitigate CrateDB bootstrap errors on Windows

Author: amotl

src/crate/testing/layer.py

@@ -248,6 +248,8 @@ def __init__(self,
         start_cmd = (crate_exec, ) + tuple(["-C%s=%s" % ((key, str(value).lower()) if type(value) == bool else (key, value))
                                             for key, value in settings.items()])
 
+        if sys.platform == 'win32':
+            start_cmd += ('-Djava.net.preferIPv4Stack=true',)
         self._wd = wd = os.path.join(CrateLayer.tmpdir, 'crate_layer', name)
         self.start_cmd = start_cmd + ('-Cpath.data=%s' % wd,)