Error on not loading a new map on top an existing one

[ugurdogrusoz]

• Load the first PD sample
• Try to load the second PD sample (Newt will ask for confirmation of continuation)
• Answer No and nothing happens with an error in the Console

[umut-er]

I tracked this issue down. It was introduced relatively recently at commit 32f7218. It was an attempt to add functionality to the confirmation view cancel button but it interfered with other processes. Luckily, since the refactoring done on the query views code, this functionality is no longer needed. I removed it. It should be fine now. Please review on the internal server.