Do not display AA mutations to undetermined (X)

When augur is run without inference of ambiguous bases we will get lots of undetermined translated codons, which we don't want to display.

src/components/tree/infoPanels/hover.js

@@ -182,28 +182,30 @@ const Mutations = ({node}) => {
   /* --------- AMINO ACID MUTATIONS --------------- */
   /* AA mutations are found at `mutations[prot_name]` -> Array of strings */
   const prots = Object.keys(mutations).filter((v) => v !== "nuc");
-  const nMutsPerProt = {};
-  let numberOfAaMuts = 0;
+
+  const mutationsToDisplay = {};
+  let shouldDisplay = false;
+
   for (const prot of prots) {
-    nMutsPerProt[prot] = mutations[prot].length;
-    numberOfAaMuts += mutations[prot].length;
+    const muts = mutations[prot].filter((mut) => !mut.endsWith("X"));
+    if (muts.length) {
+      mutationsToDisplay[prot] = muts;
+      shouldDisplay = true;
+    }
   }
-  if (numberOfAaMuts > 0) {
+  if (shouldDisplay) {
     const nDisplay = 3; // number of mutations to display per protein
     const nProtsToDisplay = 7; // max number of proteins to display
-    let protsRendered = 0;
     const mutationsToRender = [];
-    prots.forEach((prot) => {
-      if (nMutsPerProt[prot] && protsRendered < nProtsToDisplay) {
-        let x = prot + ":\u00A0\u00A0" + mutations[prot].slice(0, Math.min(nDisplay, nMutsPerProt[prot])).join(", ");
-        if (nMutsPerProt[prot] > nDisplay) {
-          x += " + " + (nMutsPerProt[prot] - nDisplay) + " more";
+    Object.keys(mutationsToDisplay).forEach((prot, idx) => {
+      if (idx < nProtsToDisplay) {
+        let x = prot + ":\u00A0\u00A0" + mutationsToDisplay[prot].slice(0, Math.min(nDisplay, mutationsToDisplay[prot].length)).join(", ");
+        if (mutationsToDisplay[prot].length > nDisplay) {
+          x += " + " + (mutationsToDisplay[prot].length - nDisplay) + " more";
         }
         mutationsToRender.push(x);
-        protsRendered++;
-        if (protsRendered === nProtsToDisplay) {
-          mutationsToRender.push(`(protein mutations truncated)`);
-        }
+      } else if (idx === nProtsToDisplay) {
+        mutationsToRender.push(`(protein mutations truncated)`);
       }
     });
     elements.push(<InfoLine name="AA mutations:" value={mutationsToRender} key="aa"/>);