Revert "Support registration & login with phone number (#742)"

This reverts commit 0269562383.

This breaks against the current synapse release. We need to think more
carefully about backwards compatibility.

src/HtmlUtils.js

@@ -58,22 +58,6 @@ export function unicodeToImage(str) {
     return str;
 }
 
-/**
- * Given one or more unicode characters (represented by unicode
- * character number), return an image node with the corresponding
- * emoji.
- *
- * @param alt {string} String to use for the image alt text
- * @param unicode {integer} One or more integers representing unicode characters
- * @returns A img node with the corresponding emoji
- */
-export function charactersToImageNode(alt, ...unicode) {
-    const fileName = unicode.map((u) => {
-        return u.toString(16);
-    }).join('-');
-    return <img alt={alt} src={`${emojione.imagePathSVG}${fileName}.svg${emojione.cacheBustParam}`}/>;
-}
-
 export function stripParagraphs(html: string): string {
     const contentDiv = document.createElement('div');
     contentDiv.innerHTML = html;