Do not throw when unable to load pba vocabularies

src/store/modules/vocabularies.js

@@ -24,9 +24,15 @@ const vocabularies = {
       const headers = {
         Authorization: `Bearer ${localStorage.getItem('access_token')}`
       }
-      const result = await axios.get(`${process.env.API_HOST}/pba/pieces`, { headers })
-      let pieces = result.data.sort((a, b) => a.label.replace(/\W/g, '').localeCompare(b.label.replace(/\W/g, '')))
-      if (limit) pieces = pieces.splice(0, limit)
+      let pieces = []
+      try {
+        const result = await axios.get(`${process.env.API_HOST}/pba/pieces`, {headers})
+        pieces = result.data.sort((a, b) => a.label.replace(/\W/g, '').localeCompare(b.label.replace(/\W/g, '')))
+        if (limit) pieces = pieces.splice(0, limit)
+      }
+      catch (err) {
+        console.error('Failed to load PBA vocabularies:', err.message || err.code)
+      }
       for (let piece of pieces) {
         const result = await axios.get(`${process.env.API_HOST}/pba/pieces/${piece.piece_id}/titles`, {headers})
         context.commit('addTermsForScope', [piece.piece_id, result.data.map(title => {