fix: <?php ?>0 in script will throw an error

[zhihuahuang]

If you use minifyJS options, a number after custom fragments in script will throw an error.

Like this:

let html = `<script>var value = "<?php ?>+<?php ?>0";</script>`;

minify(html, {
    minifyJS: true,
});

It will be throw a TypeError.

TypeError: Cannot read property '0' of undefined
    at html-minifier/src/htmlminifier.js:1266:52

I found that the cause is the regular expression uidAttr + ([0-9]+). It will match the extra numbers. So I added parentheses to the regular expression.

[alexlamsl]

Please add some test cases to demonstrate this fix. Also may I suggest uidAttr + ([0-9]+?) + uidAttr instead of adding parenthesis for better resilience.