Author: Luca Bösch
MDL-67210 tool_uploadcourse: Allow only 0 and 1 for visible value.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=2e7f4fcefd1e31461b952d16bf7b04d1e8d61930
http://github.com/moodle/moodle/commit/2e7f4fcefd1e31461b952d16bf7b04d1e8d61930
+ 3.8 en [invalidvisibilitymode,tool_uploadcourse]