Displaying a swastika is not illegal in Germany. It's only illegal if you use it for nazi propaganda purposes. Stop spreading misinformation. Relevant quote [1]:
"Whoever domestically disseminates or produces ... the contents of which are intended to further the aims of a former National Socialist organization ... shall be punished ..."
[1] https://en.wikipedia.org/wiki/Strafgesetzbuch_section_86a#Sy...