fix: restore default exchanges (#3613)

Co-authored-by: dni ⚡ <office@dnilabs.com>

lnbits/static/js/api.js

@@ -173,5 +173,10 @@ window._lnbitsApi = {
     return this.request('GET', '/api/v1/currencies').then(response => {
       return ['sats', ...response.data]
     })
+  },
+  getDefaultSetting(fieldName) {
+    return LNbits.api
+      .request('GET', `/admin/api/v1/settings/default?field_name=${fieldName}`)
+      .catch(LNbits.utils.notifyApiError)
   }
 }

lnbits/static/js/components/admin/lnbits-admin-exchange-providers.js

@@ -70,6 +70,11 @@ window.app.component('lnbits-admin-exchange-providers', {
     }
   },
   methods: {
+    getDefaultSetting(fieldName) {
+      LNbits.api.getDefaultSetting(fieldName).then(response => {
+        this.formData[fieldName] = response.data.default_value
+      })
+    },
     getExchangeRateHistory() {
       LNbits.api
         .request('GET', '/api/v1/rate/history', this.g.user.wallets[0].inkey)

lnbits/static/js/pages/admin.js

@@ -38,17 +38,9 @@ window.PageAdmin = {
   },
   methods: {
     getDefaultSetting(fieldName) {
-      LNbits.api
-        .request(
-          'GET',
-          `/admin/api/v1/settings/default?field_name=${fieldName}`
-        )
-        .then(response => {
-          this.formData[fieldName] = response.data.default_value
-        })
-        .catch(function (error) {
-          LNbits.utils.notifyApiError(error)
-        })
+      LNbits.api.getDefaultSetting(fieldName).then(response => {
+        this.formData[fieldName] = response.data.default_value
+      })
     },
     restartServer() {
       LNbits.api