Fix version

Author: adeas31

OMPython/ModelicaSystem.py

@@ -1075,7 +1075,7 @@ def simulate_cmd(
             version = self._session.sendExpression("getVersion()", parsed=True)
             print(f"OpenModelica version string: {version}")
 
-            m = re.search(r"v(\d+)\.(\d+)\.(\d+)", s)
+            m = re.search(r"v(\d+)\.(\d+)\.(\d+)", version)
             if not m:
                 raise ValueError("Version not found")