patch 9.1.1476: no easy way to deduplicate text

Problem:  no easy way to deduplicate text
Solution: add the :uniq ex command
          (Hirohito Higashi)

closes: #17538

Signed-off-by: Hirohito Higashi <h.east.727@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/proto/ex_cmds.pro b/src/proto/ex_cmds.pro
index c083cec..36cb6bd 100644
--- a/src/proto/ex_cmds.pro
+++ b/src/proto/ex_cmds.pro
@@ -2,6 +2,7 @@
 void do_ascii(exarg_T *eap);
 void ex_align(exarg_T *eap);
 void ex_sort(exarg_T *eap);
+void ex_uniq(exarg_T *eap);
 int do_move(linenr_T line1, linenr_T line2, linenr_T dest);
 void ex_copy(linenr_T line1, linenr_T line2, linenr_T n);
 void free_prev_shellcmd(void);