patch 9.1.0511: CursorMovedC triggered wrongly with setcmdpos()

Problem:  CursorMovedC triggered wrongly with setcmdpos()
          (after v9.1.0507)
Solution: Remove the premature triggering.  Also don't trigger when
          cursor didn't move. (zeertzjq)

closes: #15064

Signed-off-by: zeertzjq <zeertzjq@outlook.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index 27ab2c7..e19d601 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -1,4 +1,4 @@
-*autocmd.txt*   For Vim version 9.1.  Last change: 2024 Jun 20
+*autocmd.txt*   For Vim version 9.1.  Last change: 2024 Jun 21
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -751,7 +751,8 @@
 				that is slow.
 							*CursorMovedC*
 CursorMovedC			After the cursor was moved in the command
-				line. Be careful not to mess up the
+				line while the text in the command line hasn't
+				changed.  Be careful not to mess up the
 				command line, it may cause Vim to lock up.
 				<afile> is set to a single character,
 				indicating the type of command-line.