Rename string validation test model

Author: Alexander Pann

code/languages/org.iets3.opensource/tests/test.in.expr.os/models/[email protected] renamed to code/languages/org.iets3.opensource/tests/test.in.expr.os/models/[email protected]

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<model ref="r:4498a3f1-ffdc-46cb-b225-63bf7159e69e(test.in.expr.os.stringvaliation@tests)">
+<model ref="r:4498a3f1-ffdc-46cb-b225-63bf7159e69e(test.in.expr.os.stringvalidation@tests)">
   <persistence version="9" />
   <languages>
     <use id="8585453e-6bfb-4d80-98de-b16074f1d86c" name="jetbrains.mps.lang.test" version="5" />