fix: don't die if manNumberRegex doesn't match the glob (npm#4610)

In certain edge cases, the glob could find files that manNumberRegex wouldn't match.

A possible solution would be to try to bring the two closer, but since globs and regexes are different syntaxes, the two will never be exactly the same.
It's always asking for bugs; better to just handle the issue directly.

lib/commands/help.js

@@ -61,9 +61,10 @@ class Help extends BaseCommand {
     const f = `${manroot}/${manSearch}/?(npm-)${section}.[0-9]*`
     let mans = await glob(f)
     mans = mans.sort((a, b) => {
-      // Because of the glob we know the manNumberRegex will pass
-      const aManNumber = a.match(manNumberRegex)[1]
-      const bManNumber = b.match(manNumberRegex)[1]
+      // Because the glob is (subtly) different from manNumberRegex,
+      // we can't rely on it passing.
+      const aManNumber = (a.match(manNumberRegex) || Infinity)[1]
+      const bManNumber = (b.match(manNumberRegex) || Infinity)[1]
 
       // man number sort first so that 1 aka commands are preferred
       if (aManNumber !== bManNumber) {