po: Update translations to build with gettext 0.26

Gettext 0.26 validates format strings. In some cases before
the GRUB build process was converting newlines sequences (\n)
to (\<translated character>) which is invalid. Update the
impacted language sed script files to ensure newlines use
the correct escape sequence.

This avoids build errors such as:

  de@hebrew.po:8192: 'msgstr' is not a valid Shell printf format string, unlike 'msgid'. Reason: This escape sequence is invalid.

Fixes: https://savannah.gnu.org/bugs/?67353

Signed-off-by: Andrew Hamilton <adhamilt@gmail.com>
Reviewed-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

po/arabic.sed

@@ -81,3 +81,5 @@ s,%\([0-9]*\)زو,%\1zu,g
 s,%\([0-9]*\)كس,%\1x,g
 s,%\([0-9]*\)لكس,%\1lx,g
 s,%\([0-9]*\)للكس,%\1llx,g
+
+s,\\ن,\\n,g

po/cyrillic.sed

@@ -104,3 +104,5 @@ s,%\([0-9]*\)зу,%\1zu,g
 s,%\([0-9]*\)ѯ,%\1x,g
 s,%\([0-9]*\)лѯ,%\1lx,g
 s,%\([0-9]*\)ллѯ,%\1llx,g
+
+s,\\н,\\n,g

po/greek.sed

@@ -106,3 +106,5 @@ s,%\([0-9]*\)ζυ,%\1zu,g
 s,%\([0-9]*\)ξ,%\1x,g
 s,%\([0-9]*\)λξ,%\1lx,g
 s,%\([0-9]*\)λλξ,%\1llx,g
+
+s,\\ν,\\n,g

po/hebrew.sed

@@ -89,3 +89,5 @@ s,%\([0-9]*\)זוּ,%\1zu,g
 s,%\([0-9]*\)כּס,%\1x,g
 s,%\([0-9]*\)לכּס,%\1lx,g
 s,%\([0-9]*\)ללכּס,%\1llx,g
+
+s,\\נ,\\n,g