patch 9.0.0958: messages test is flaky

Problem:    Messages test is flaky.
Solution:   Add a short delay.

src/testdir/dumps/Test_verbose_system_1.vim

@@ -1,3 +1,5 @@
 " Filter that removes the ever changing temp directory name from the screendump
 " that shows the system() command executed.
-1s+|t|m|p|/|.|.|.*| |+|t|m|p|/|x|x|x|x|x|x|x|/|1| |+
+" This should be on the first line, but if it isn't there ignore the error,
+" the screendump will then show the problem.
+1s+|t|m|p|/|.|.|.*| |+|t|m|p|/|x|x|x|x|x|x|x|/|1| |+e

src/testdir/dumps/Test_verbose_system_2.vim

@@ -1,3 +1,5 @@
 " Filter that removes the ever changing temp directory name from the screendump
 " that shows the system() command executed.
-1s+|t|m|p|/|.|.|.*| |+|t|m|p|/|x|x|x|x|x|x|x|/|1| |+
+" This should be on the first line, but if it isn't there ignore the error,
+" the screendump will then show the problem.
+1s+|t|m|p|/|.|.|.*| |+|t|m|p|/|x|x|x|x|x|x|x|/|1| |+e

src/testdir/test_messages.vim

@@ -349,7 +349,7 @@ func Test_echo_verbose_system()
 
   " display a page and go back, results in exactly the same view
   call term_sendkeys(buf, ' ')
-  call TermWait(buf)
+  call TermWait(buf, 50)
   call term_sendkeys(buf, 'b')
   call VerifyScreenDump(buf, 'Test_verbose_system_1', {})
 
@@ -362,7 +362,7 @@ func Test_echo_verbose_system()
   call VerifyScreenDump(buf, 'Test_verbose_system_2', {})
 
   call term_sendkeys(buf, ' ')
-  call TermWait(buf)
+  call TermWait(buf, 50)
   call term_sendkeys(buf, 'b')
   call VerifyScreenDump(buf, 'Test_verbose_system_2', {})
 

src/version.c

@@ -695,6 +695,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    958,
 /**/
     957,
 /**/