WebGui error for method cache miss doesn't print params correctly

[AutonomicPerfectionist]

Describe the bug
WebGui uses toString() on msg.data for an error message, which just prints out a useless string like [Ljava.lang.Object@40e45e11, code is here:

myrobotlab/src/main/java/org/myrobotlab/service/WebGui.java

Line 702 in b936905

error("method cache could not find %s.%s(%s)", clazz.getSimpleName(), msg.method, msg.data);

Should be using Arrays.toString()