#5474 password is cut when it contains # postfix

[WebminBugReport]

OS: Ubuntu 20.04 LTS
browser: Firefox, Chrome
Webmin: current version: 1.973 (but was detected on an 10 years old installation also).

When I add a password containing a '#' it is cut when the config site is reloaded.
In order to reproduce proceed as follows:
Install Postfix -> got to "SMTP Authentication And Encryption". At the bottom of the site: SMTP login to outgoing mail host: select
Login as xxxx with password "123#thisisnotdisplayed". Then save and reopen SMTP Authentication And Encryption. You will discover that only 123 is shown instead of 123#thisisnotdisplayed , so without readding the password again, it is saved wrongly.

[Jamie Cameron]

This is a bug due to the # being interpreted as a comment character. We'll fix this in the next release of Webmin.