patch 8.0.1189: E172 is not actually useful

Problem:    E172 is not actually useful, it's only on Unix anyway.
Solution:   Remove the check and the error.

runtime/doc/message.txt

@@ -463,12 +463,6 @@ changed.  To avoid the message reset the 'warn' option.
 Something inside Vim went wrong and resulted in a NULL pointer.  If you know
 how to reproduce this problem, please report it. |bugs|
 
-							*E172*  >
-  Only one file name allowed
-
-The ":edit" command only accepts one file name.  When you want to specify
-several files for editing use ":next" |:next|.
-
 						*E41* *E82* *E83* *E342*  >
   Out of memory!
   Out of memory!  (allocating {number} bytes)

src/ex_docmd.c

@@ -5085,29 +5085,6 @@ expand_filename(
 	{
 	    if (n == 2)
 	    {
-#ifdef UNIX
-		/*
-		 * Only for Unix we check for more than one file name.
-		 * For other systems spaces are considered to be part
-		 * of the file name.
-		 * Only check here if there is no wildcard, otherwise
-		 * ExpandOne() will check for errors. This allows
-		 * ":e `ls ve*.c`" on Unix.
-		 */
-		if (!has_wildcards)
-		    for (p = eap->arg; *p; ++p)
-		    {
-			/* skip escaped characters */
-			if (p[1] && (*p == '\\' || *p == Ctrl_V))
-			    ++p;
-			else if (VIM_ISWHITE(*p))
-			{
-			    *errormsgp = (char_u *)_("E172: Only one file name allowed");
-			    return FAIL;
-			}
-		    }
-#endif
-
 		/*
 		 * Halve the number of backslashes (this is Vi compatible).
 		 * For Unix and OS/2, when wildcards are expanded, this is

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1189,
 /**/
     1188,
 /**/