translation: regenerate vim.pot, ignore version.c changes

Regenerate vim.pot because of a wording update in optwin.vim for the
diffanchors feature.

While at it, update the textconv filter to ignore all lines
containing version.c because those change just by incrementing
the Vim patch number *grummel*

Signed-off-by: Christian Brabandt <cb@256bit.org>

.gitattributes

@@ -1,6 +1,9 @@
 src/testdir/test42.in diff
 
-# ignore vim.pot creation date when diffing
+# vim.pot may change just by incrementing a patch number
+# so ignore the following differences:
+# - POT-Creation Date
+# - comments in version.c for line numbers:
 # set this up using:
-# git config diff.ignore_pot_date.textconv 'grep -v "^.POT-Creation-Date:.*"'
+# git config diff.ignore_pot_date.textconv 'grep -Ev "^.(POT-Creation-Date:|.*version\.c).*"'
 src/po/vim.pot diff=ignore_pot_date