Consistent exposure of nested parameter type in binding exceptions

(cherry picked from commit ed54895)

spring-web/src/main/java/org/springframework/web/bind/MissingPathVariableException.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -51,7 +51,7 @@ public class MissingPathVariableException extends ServletRequestBindingException
 	@Override
 	public String getMessage() {
 		return "Missing URI template variable '" + this.variableName +
-				"' for method parameter of type " + this.parameter.getParameterType().getSimpleName();
+				"' for method parameter of type " + this.parameter.getNestedParameterType().getSimpleName();
 	}
 
 	/**