options: warn when option -O or -S is given, and ignore them

If these two command-line options would override an rcfile setting of
their counterpart new option, the user might come to expect being able
to do this also in the future.  But these old options will be obsoleted
at some moment, so... better start ignoring them right now.

src/nano.c

@@ -2151,7 +2151,8 @@ int main(int argc, char **argv)
 				break;
 #endif
 			case 'O':
-				UNSET(EMPTY_LINE);
+				fprintf(stderr, N_("Option %s is ignored; it is the default\n"),
+										"morespace");
 				break;
 #ifdef ENABLE_HISTORIES
 			case 'P':
@@ -2168,7 +2169,8 @@ int main(int argc, char **argv)
 				break;
 #ifndef NANO_TINY
 			case 'S':
-				UNSET(JUMPY_SCROLLING);
+				fprintf(stderr, N_("Option %s is ignored; it is the default\n"),
+										"smooth");
 				break;
 #endif
 			case 'T':