[TASK] User settings: move flashMessage notice

There is a permanent flashMessage in user settings module to indicate
the possible necessity to reload the whole backend after changing
settings.
Move the reload notice in user settings module to the top and display
it only after saving.

Change-Id: I3189e8b4fc47e5bf22c23aa7e02ee9b04abd2705
Resolves: #32891
Releases: 4.7
Reviewed-on: http://review.typo3.org/7639
Reviewed-by: Philipp Gampe
Tested-by: Philipp Gampe
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Oliver Klee
Reviewed-by: Tolleiv Nietsch
Tested-by: Tolleiv Nietsch
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter