Fix coding standards

The test bot once again reports a few coding standards violation – apparently, deprecation messages in trigger_error() shouldn’t contain a period after the URL (which makes sense).
One baffling thing, though, is that the test bot’s ESLint report states that the $ in line 6 of js/search_api.processors.js should be wrapped in parentheses, while my local ESLint reports complains when I do that. So, I will leave that as-is for now (to not be irritated during local development), but would very much like to know the explanation, and make my local results consistent with the test bot.