Include parameter name in exception when value is invalid

When typing a value into a free-form text field, the system errors out with an error message that isn't helpful for understanding which parameter is wrong.

Include the parameter name along with the value in the exception message.

```
Caused by: java.lang.IllegalArgumentException: Illegal choice: no
	at hudson.model.ChoiceParameterDefinition.checkValue(ChoiceParameterDefinition.java:75)
	at hudson.model.ChoiceParameterDefinition.createValue(ChoiceParameterDefinition.java:83)
	at com.sonyericsson.rebuild.RebuildAction.getParameterValue(RebuildAction.java:329)
	at com.sonyericsson.rebuild.RebuildAction.doConfigSubmit(RebuildAction.java:229)
	at sun.reflect.GeneratedMethodAccessor258.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.kohsuke.stapler.Function$InstanceFunction.invoke(Function.java:298)
	at org.kohsuke.stapler.Function.bindAndInvoke(Function.java:161)
	at org.kohsuke.stapler.Function.bindAndInvokeAndServeResponse(Function.java:96)
	at org.kohsuke.stapler.MetaClass$1.doDispatch(MetaClass.java:120)
	at org.kohsuke.stapler.NameBasedDispatcher.dispatch(NameBasedDispatcher.java:53)
	at org.kohsuke.stapler.Stapler.tryInvoke(Stapler.java:728)
	... 69 more
```