MINOR: ssl: Remove debug fprintf in 'update ssl ocsp-response' cli command

A debug fprintf was left behind in the new cli function.
diff --git a/src/ssl_ocsp.c b/src/ssl_ocsp.c
index bda7a1b..1271f6e 100644
--- a/src/ssl_ocsp.c
+++ b/src/ssl_ocsp.c
@@ -1420,7 +1420,9 @@
 			}
 		}
 		if (!found) {
-			fprintf(stderr, "Missing 'Content-Type: application/ocsp-response' header\n");
+			chunk_printf(&trash, "Missing 'Content-Type: application/ocsp-response' header\n");
+			if (applet_putchk(appctx, &trash) == -1)
+				goto more;
 			goto end;
 		}
 		ctx->flags &= ~HC_F_RES_HDR;