Remove additional examples in cases of errors and handled error check

Because it was causing issues with ztail kind of exercises where the
program can fail but the error message can be any line

go/tests/lib/lib.go

@@ -389,23 +389,7 @@ func ChallengeMainStdin(exercise, input string, args ...string) {
 				code(studentCode) + "\n\n" +
 				"Expected :\n" +
 				console(solution) +
-				code(solutionCode) + "\n\n" +
-				"Another example :\n" +
-				console("ERROR\n") +
-				code(1))
-		}
-		firstLine := strings.SplitN(student, "\n", 1)[0]
-		handledError := strings.Contains(firstLine, "ERROR")
-		if !handledError {
-			Fatalln(`Your program does not handle the error, the first line of the output must contain "ERROR" :` + "\n" +
-				console(student) +
-				code(studentCode) + "\n\n" +
-				"Expected :\n" +
-				console(solution) +
-				code(solutionCode) + "\n\n" +
-				"Another example :\n" +
-				console("ERROR\n") +
-				code(1))
+				code(solutionCode))
 		}
 	}
 	if student != solution {