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=6c4fda02504cced232de2c66b65c465b0190fe80
http://github.com/moodle/moodle/commit/6c4fda02504cced232de2c66b65c465b0190fe80
+ 3.7 en [invalidvisibilitymode,tool_uploadcourse]