If available, ensure that Analytics' regions are "us" and "de" (not "eu")

[aseure]

We've recently discovered that at least one API client was exposing "eu" as a
valid region for the Analytics client implementation, which is wrong. Only the
following regions are available at the moment to the Analytics client:

• "us"
• "de"

[Haroenv]

only .us seems to be available

algoliasearch-client-scala/src/main/scala/algolia/AlgoliaClient.scala

Lines 97 to 101 in aa3fa2f

	/* Personalization default host is set as 'var' because the region might be overridden. */
	var personalizationHost: String = "https://personalization.us.algolia.com"
	@deprecated("use personalization instead", "1.40.0")
	var recommendationHost: String = "https://recommendation.us.algolia.com"