handling copyright returned in GetMetadata instead of in GetFeatureInfo

New ncWMS servers return the copyright attribute in GetMetadata instead of in GetFeatureInfo, we're using the copyright field to describe the map. Now the behavior is fixed and the map description is returned properly.
#179 Preserving old behaviour of copyright

Since copyright was returned both in GetMetadata and GetFeatureInfo and we relied on GetFeatureInfo, we'll continue to use the response in GetFeatureInfo if there is one and if not we'll use the one in GetMetadata
Merge pull request #204 from aodn/issue-179

handling copyright returned in GetMetadata instead of in GetFeatureInfo