Camel Proxy ignores camelContextId property in Spring configuration

Camel Proxy, if configured outside camelContext element in Spring configuration, ignores camelContextId property. (Actual code only cares about this property, if camelContext isn't set - which it always is by then.)

Steps to reproduce: Configure two contexts in spring configuration. Then in the same config file configure two proxies, each pointing to the same URI, but with different camelContextId specified. Both proxies will be created pointing to the same (first) camel context, despite being configured to different contexts.