Warn if we see a BANNER command when the banner has already been issued.

src/main.c

@@ -1486,6 +1486,10 @@ static int DoBanner(ParsePtr p)
     }
     if (!c) return E_EOLN;
 
+    if (DidMsgReminder) {
+        Wprint(tr("Banner has already been issued; this BANNER command will have no effect"));
+    }
+
     while(c) {
         if (DBufPutc(&buf, c) != OK) return E_NO_MEM;
         c = ParseChar(p, &err, 0);

tests/test.cmp

@@ -25085,6 +25085,7 @@ TRANSLATE "%s(%d): IF without ENDIF" ""
 TRANSLATE "%s(%s): ["["]#%d] %s function `%s'" ""
 TRANSLATE "(Security note: $RunOff variable tested.)" ""
 TRANSLATE "Accepting \"%s\" for $Latitude/$Longitude, but you should use the \"C\" locale decimal separator \".\" instead" ""
+TRANSLATE "Banner has already been issued; this BANNER command will have no effect" ""
 TRANSLATE "Caching directory `%s' listing" ""
 TRANSLATE "Caching file `%s' in memory" ""
 TRANSLATE "Called from" ""