Remove MPS 2019 entry from readme

Author: Alexander Pann

README.md

@@ -26,7 +26,6 @@ For details see [wiki](https://github.com/IETS3/iets3.opensource/wiki/Supported-
 - MPS 2020.3 (branch: [maintenance/mps20203](https://github.com/IETS3/iets3.opensource/tree/maintenance/mps20203)) 
 - MPS 2020.2 (branch: [maintenance/mps20202](https://github.com/IETS3/iets3.opensource/tree/maintenance/mps20202)) 
 - MPS 2020.1 (branch: [maintenance/mps20201](https://github.com/IETS3/iets3.opensource/tree/maintenance/mps20201)) 
-- MPS 2019.3 (branch: [maintenance/mps20193](https://github.com/IETS3/iets3.opensource/tree/maintenance/mps20193)) 
 
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