No regex url check for EmbedBuilder

[xDec0de]

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Changes

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Description

Just a simple change to avoid using a regex Pattern when checking if a URL is valid on the EmbedBuilder class. Instead, it relies on String#regionMatches (Case insensitive) and a simple length check to have the exact same behaviour as the current pattern. I know this may be considered micro optimization, but I found it and thought it could be an easy first PR for me.

[xDec0de]

Oh, I forgot to mention that I was going to deprecate EmbedBuilder#URL_PATTERN in favor of EmbedBuilder#isUrlOrAttachment, but I decided not to and leave that decision to the maintainers.