Fixed a Bug finding an Assertion Error

build.gradle

src/main/java/de/b2tla/TLCRunner.java

src/main/java/de/b2tla/prettyprint/TLAPrinter.java

src/main/java/de/b2tla/tla/Generator.java

src/main/java/de/b2tla/tlc/TLCOutput.java

src/test/java/de/b2tla/tlc/integration/ErrorTest.java

...t/java/de/b2tla/tlc/integration/SingleConfigurations.java

...b2tla/tlc/integration/probprivate/AssertionErrorTest.java

...va/de/b2tla/tlc/integration/probprivate/DeadlockTest.java

...t/java/de/b2tla/tlc/integration/probprivate/GoalTest.java

...a/tlc/integration/probprivate/InvariantViolationTest.java

...t/java/de/b2tla/tlc/integration/probprivate/LawsTest.java

...ava/de/b2tla/tlc/integration/probprivate/NoErrorTest.java

...2tla/tlc/integration/probprivate/WellDefinednessTest.java

src/test/resources/errors/AssertionError.mch

src/test/resources/errors/AssertionError2.mch