Jira advanced settings may be reverted to the default value if another setting is updated by pressing return/enter in the keyboard

Issue Summary

From the Jira advanced settings, updating any setting by pressing return/enter from the keyboard it may revert other settings to their default value.

Steps to Reproduce

1. Go to Jira Advanced Settings
2. Change the value of jira.attachment.number.of.zip.entries
3. Change the value of jira.clone.prefix and press ENTER from the keyboard
4. The value of jira.attachment.number.of.zip.entries is reverted to default

1. Go to Jira Advanced Settings
2. Change the value of jira.date.time.picker.java.format
3. Change the value of jira.data.picker.javascript.format and press ENTER from the keyboard
4. The value of jira.date.time.picker.java.format is reverted to default

The issue is reproducible with all the Advanced fields at the following way:
Pressing ENTER on input field will revert first custom value from top to bottom.
Setting 10 custom values and then press enter on some value after them for 10 times - all 10 values will be reverted one after each other

I attached a screen recording of the issue:

Workaround

Modify the values by clicking the Update button in the UI.

One may also add the following JavaScript code to the announcement banner to prevent enter/return from working on this page.

<script type="text/javascript">
    AJS.toInit(function(){
        if (document.URL.indexOf("/secure/admin/AdvancedApplicationProperties.jspa") >= 0){
            // Enabling workaround for JRASERVER-69900 preventing enter/return keypress
            AJS.$(document).keypress(
            function(event){
                if (event.which == '13') {
                event.preventDefault();
                }
            });
        }
    });
</script>