Push to GraphDB with Custom objects

#### Description:
When pushing data containing a custom object with a property name that contains a whitespace character, the result data from the http put request gives the warning below and data will not be overwritten in graphDB. This problem can be avoided by separating property names with underscores instead of whitespaces. A potential other fix would be to check the property names before converting them to TTL and replacing whitespaces.

Another fix might be to indicate a potential naming convention to the user. Currently the only sign of data not being updated is the amount of statements in the GraphDB repository, there are no warnings or errors being thrown in Grasshopper. The idea with this fix would be to display the response from the http request and prompt the user with a possible solution.

_Grasshopper definition of the custom object with property (site location) containing the whitespace._

_Http response with warning_