patch 8.2.0305: relativenumber test fails on some systems

Problem:    Relativenumber test fails on some systems. (James McCoy)
Solution:   Clear the command line.

Author: brammool

src/testdir/dumps/Test_relnr_colors_2.dump

@@ -7,4 +7,4 @@
 | +0#ff404010&@1|2| |1+0#0000000&@1|2| @42
 | +0#ff404010&@1|3| |1+0#0000000&@1|3| @42
 | +0#ff404010&@1|4| |1+0#0000000&@1|4| @42
-|:|h|i| |L|i|n|e|N|r|A|b|o|v|e| |c|t|e|r|m|f|g|=|b|l|u|e| @3|1@2|,|1| @8|5@1|%| 
+|:| @30|1@2|,|1| @8|5@1|%| 

src/testdir/dumps/Test_relnr_colors_3.dump

@@ -7,4 +7,4 @@
 | +0#40ff4011&@1|2| |1+0#0000000&@1|2| @42
 | +0#40ff4011&@1|3| |1+0#0000000&@1|3| @42
 | +0#40ff4011&@1|4| |1+0#0000000&@1|4| @42
-|:|h|i| |L|i|n|e|N|r|B|e|l|o|w| |c|t|e|r|m|f|g|=|g|r|e@1|n| @2|1@2|,|1| @8|5@1|%| 
+|:| @30|1@2|,|1| @8|5@1|%| 

src/testdir/test_number.vim

@@ -284,10 +284,10 @@ func Test_relativenumber_colors()
   " Default colors
   call VerifyScreenDump(buf, 'Test_relnr_colors_1', {})
 
-  call term_sendkeys(buf, ":hi LineNrAbove ctermfg=blue\<CR>")
+  call term_sendkeys(buf, ":hi LineNrAbove ctermfg=blue\<CR>:\<CR>")
   call VerifyScreenDump(buf, 'Test_relnr_colors_2', {})
 
-  call term_sendkeys(buf, ":hi LineNrBelow ctermfg=green\<CR>")
+  call term_sendkeys(buf, ":hi LineNrBelow ctermfg=green\<CR>:\<CR>")
   call VerifyScreenDump(buf, 'Test_relnr_colors_3', {})
 
   call term_sendkeys(buf, ":hi clear LineNrAbove\<CR>")

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    305,
 /**/
     304,
 /**/