[458544] Impossible to save value of text att if left not editable.

EMFCompareTextMergeViewer now checks the relevant side instead of always
checking the left side.

Bug: 458544
Change-Id: Ia3118f10d8ee280cf0d1a9b32a65c1366c043baf
Signed-off-by: Laurent Delaigue <laurent.delaigue@obeo.fr>
2 files changed