Description of problem: 

Move the info alert when editing a pipeline from the pipeline section to the build config section and change the text.

When the builder image is changed:

"Changing to this builder image will update your associated Pipeline and remove any customization you may have applied."

When an unsupported builder image is selected:

"There are no supported pipelines available for ‘insert name of builder image’. Changing to this builder image will disconnect your associated Pipeline."