professional: fix typo in Erasmus+ years

content/pages/professional-de.md

@@ -71,7 +71,7 @@ Als überzeugter Anhänger von Freier & Open Source Software möchte ich nicht n
 
 #### Erasmus+ Auslandssemester an der [Tampere University of Technology](https://www.tuni.fi/en/about-us/tampere-university)
 
-📍 Tampere, Finnland 🗓 08/2017 – 12/2018
+📍 Tampere, Finnland 🗓 08/2017 – 12/2017
 
 - Studienfächer: Informatik, Kommunikationstechnologie
 

content/pages/professional-en.md

@@ -72,7 +72,7 @@ I am passionate about Free and Open Source software and would like to work not o
 
 #### Erasmus+ studies abroad at [Tampere University of Technology](https://www.tuni.fi/en/about-us/tampere-university)
 
-📍 Tampere, Finland 🗓 08/2017 – 12/2018
+📍 Tampere, Finland 🗓 08/2017 – 12/2017
 
 - studies of computer science and communication technologies