fix #6645 -- jupyter image width bug

Author: williamstein

src/packages/frontend/jupyter/_jupyter.sass

@@ -9,7 +9,6 @@
 .cocalc-jupyter-rendered
   img
     max-width: 100%
-    height: auto
   table
     border: none
     border-collapse: collapse

src/packages/frontend/jupyter/output-messages/image.tsx

@@ -41,12 +41,12 @@ export const Image: React.FC<ImageProps> = React.memo((props: ImageProps) => {
   function render_image(src, on_error?): JSX.Element {
     const props = {
       src,
-      width: width,
-      height: height,
+      width,
+      height,
     };
     props["style"] = {
       maxWidth: "100%",
-      height: "auto",
+      height: props.height ?? "auto",
     } as React.CSSProperties;
     if (on_error != null) {
       props["onError"] = on_error;