[BUGFIX] Install tool: Use sRGB colorspace in presets

Image Magick versions 6.7 and above need sRGB as colorspace,
otherwise images are too dark. This also works for older versions
like 6.6. Use sRGB as default is image configuration presets.

Change-Id: I7c50ee932b1335892eb228b10fc00136cfc54527
Resolves: #52017
Releases: 6.2
Reviewed-on: https://review.typo3.org/23840
Reviewed-by: Steffen Müller
Tested-by: Steffen Müller
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters