i18n: fix "% inside _()" problems Before this patch, "contrib/check-code.py" can't detect these problems, because the regexp pattern to detect "% inside _()" doesn't suppose the case that the format string and "%" aren't placed in the same line. This patch replaces "\s" in that regexp pattern with "[ \t\n]" to detect "% inside _()" problems in such case. "[\s\n]" can't be used in this purpose, because "\s" is automatically replaced with "[ \t]" by "_preparepats()" and "\s" in "[]" causes nested "[]" unexpectedly.