Saying you don't want immigration isn't racist if it applies to more than just immigration from certain racial groups.

However, her tweet was not about that. She called out Muslims as having certain behaviors which is clearly racist.

(Source: Oxford English Dictionary https://en.oxforddictionaries.com/definition/racism)

Volksverhetzung is not about "inciting hatred", which does not convey the concept. This article also isn't about Volksverhetzung, it's about the NetzDG, a new law.