patch 8.0.1308: the "Reading from stdin" message may be undesired

Problem:    The "Reading from stdin" message may be undesired and there is no
            easy way to skip it.
Solution:   Don't show the message with --not-a-term was used.

src/fileio.c

@@ -849,6 +849,8 @@ readfile(
 	 */
 	if (read_stdin)
 	{
+	    if (!is_not_a_term())
+	    {
 #ifndef ALWAYS_USE_GUI
 		mch_msg(_("Vim: Reading from stdin...\n"));
 #endif
@@ -861,6 +863,7 @@ readfile(
 		}
 #endif
 	    }
+	}
 	else if (!read_buffer)
 	    filemess(curbuf, sfname, (char_u *)"", 0);
     }

src/version.c

@@ -766,6 +766,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1308,
 /**/
     1307,
 /**/