follow-up fix for OSC color sequences, return

Otherwise the message "erresc: unknown str" is printed.

Reference:
https://git.suckless.org/st/commit/273db5ceaf392e68c2faf8f7dec14ea2e25e980d.html

Author: sighook

st.c

@@ -2020,7 +2020,7 @@ strhandle(void)
 				fprintf(stderr, "erresc: invalid foreground color: %s\n", p);
 			else
 				redraw();
-			break;
+			return;
 		case 11:
 			if (narg < 2)
 				break;
@@ -2033,7 +2033,7 @@ strhandle(void)
 				fprintf(stderr, "erresc: invalid background color: %s\n", p);
 			else
 				redraw();
-			break;
+			return;
 		case 12:
 			if (narg < 2)
 				break;
@@ -2046,7 +2046,7 @@ strhandle(void)
 				fprintf(stderr, "erresc: invalid cursor color: %s\n", p);
 			else
 				redraw();
-			break;
+			return;
 		case 4: /* color set */
 			if (narg < 3)
 				break;