Fix timer control missing from issue view on Jira DC/Server 10+

[reikjarloekl]

Problem

Fixes #425.

After upgrading a Jira Data Center/Server instance to Jira 10, the worklog timer control no longer appears in the issue-view command bar (it used to sit next to the Edit / Comment buttons).

Root cause

applyIssueLogic() locates the DC/Server toolbar with:

div.issue-header-content .command-bar .ops-menus > div:first-child > div:first-child

In Jira 10 the AUI toolbar structure is:

.ops-menus.aui-toolbar2
  └─ div.aui-toolbar2-inner        ← ".ops-menus > div:first-child"  ✓ (a <div>)
       ├─ ul.aui-toolbar2-primary  ← "> div:first-child"  ✗ it's a <ul>, not a <div>
       └─ div.aui-toolbar2-secondary

The final > div:first-child expects a <div>, but the first child of .aui-toolbar2-inner is now <ul class="aui-toolbar2-primary">. The selector matches nothing, so el.length === 0 and the function returns early — the timer control is never injected.

Fix

Keep the original selector as the primary lookup (unchanged behaviour on pre-10 Jira, so no regression there) and fall back to the stable .aui-toolbar2-inner container only when the original finds nothing (Jira 10+):

el = $('div.issue-header-content .command-bar .ops-menus > div:first-child > div:first-child');
if (!el.length) {
    el = $('div.issue-header-content .command-bar .ops-menus .aui-toolbar2-inner');
}

Verification

• Reproduced against a real Jira DC 10.3.x issue page: the original selector returns 0 matches; the fallback returns 1, and the injected control lands in the same toolbar as the Edit button.
• Built the extension and confirmed the fix in the bundled content script; timer control confirmed working in the issue view on Jira DC 10.
• Backward compatible by construction: pre-10 Jira uses the untouched primary selector.