Fix: a test relied on faulty behavior (#5028)

`assert.throws` did not test for the error message so far. This
changes it to actually test for the error message.

Author: BridgeAR

test/exception_handling.coffee

@@ -8,7 +8,7 @@ nonce = {}
 # Throw
 
 test "basic exception throwing", ->
-  throws (-> throw 'error'), 'error'
+  throws (-> throw 'error'), /^error$/
 
 
 # Empty Try/Catch/Finally