i18n: make the translation of -u advice in one go

The advice (consider use of -u when read_directory takes too long) is
separated into 3 different status_printf_ln() calls, and which brings
trouble for translators.

Since status_vprintf() called by status_printf_ln() can handle eol in
buffer, we could simply join these lines into one paragraph.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

wt-status.c

@@ -1027,14 +1027,10 @@ void wt_status_print(struct wt_status *s)
 		if (advice_status_u_option && 2000 < s->untracked_in_ms) {
 			status_printf_ln(s, GIT_COLOR_NORMAL, "");
 			status_printf_ln(s, GIT_COLOR_NORMAL,
-				 _("It took %.2f seconds to enumerate untracked files."
-				   "  'status -uno'"),
-				 s->untracked_in_ms / 1000.0);
-			status_printf_ln(s, GIT_COLOR_NORMAL,
-				 _("may speed it up, but you have to be careful not"
-				   " to forget to add"));
-			status_printf_ln(s, GIT_COLOR_NORMAL,
-				 _("new files yourself (see 'git help status')."));
+					 _("It took %.2f seconds to enumerate untracked files. 'status -uno'\n"
+					   "may speed it up, but you have to be careful not to forget to add\n"
+					   "new files yourself (see 'git help status')."),
+					 s->untracked_in_ms / 1000.0);
 		}
 	} else if (s->commitable)
 		status_printf_ln(s, GIT_COLOR_NORMAL, _("Untracked files not listed%s"),