Materialized generic class resolved incorrectly

When a generic interface is materialized with varying type parameters, it seems to confuse one for the other:

```java
public static void main(String[] args) throws Exception {
ObjectMapper mapper = new ObjectMapper()
.registerModule(new MrBeanModule());

mapper.readValue("{\"a\":{\"x\":\"1\"},\"b\":{\"x\":\"B\"}}", Outer.class);
}

public static class Outer {
public Inner a;
public Inner b;
}

public interface Inner {
T getX();
}
```
Output:
```
Exception in thread "main" com.fasterxml.jackson.databind.exc.InvalidFormatException: Cannot deserialize value of type `java.lang.Integer` from String "B": not a valid `java.lang.Integer` value
at [Source: (String)"{"a":{"x":"1"},"b":{"x":"B"}}"; line: 1, column: 25] (through reference chain: Scratch$Outer["b"]->com.fasterxml.jackson.module.mrbean.generated.Scratch$Inner["x"])
at com.fasterxml.jackson.databind.exc.InvalidFormatException.from(InvalidFormatException.java:67)
at com.fasterxml.jackson.databind.DeserializationContext.weirdStringException(DeserializationContext.java:1991)
at com.fasterxml.jackson.databind.DeserializationContext.handleWeirdStringValue(DeserializationContext.java:1219)
at com.fasterxml.jackson.databind.deser.std.StdDeserializer._parseInteger(StdDeserializer.java:840)
at com.fasterxml.jackson.databind.deser.std.StdDeserializer._parseInteger(StdDeserializer.java:820)
at com.fasterxml.jackson.databind.deser.std.NumberDeserializers$IntegerDeserializer.deserialize(NumberDeserializers.java:531)
at com.fasterxml.jackson.databind.deser.std.NumberDeserializers$IntegerDeserializer.deserialize(NumberDeserializers.java:506)
at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:129)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:314)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:177)
at com.fasterxml.jackson.databind.deser.impl.FieldProperty.deserializeAndSet(FieldProperty.java:138)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:314)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:177)
at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:323)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4674)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3629)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3597)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:177)
at com.fasterxml.jackson.databind.deser.impl.FieldProperty.deserializeAndSet(FieldProperty.java:138)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:314)
at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:177)
at com.fasterxml.jackson.databind.deser.DefaultDeserializationContext.readRootValue(DefaultDeserializationContext.java:323)
at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4674)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3629)
at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3597)
```
Why does it think `b.x` should be an `Integer`?