Enable rule `array-callback-return`

We had two cases that we forgot the return for a `map`
when we should have one.

Enabling the eslintrule can help us prevent from that.

Change-Id: I20d7ccbf32cfe6e43bbeb6f6c87211f429b5c588

polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor.js

diff --git a/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor.js b/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor.js
index 6c6ad01..d1bc7eb 100644
--- a/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor.js
+++ b/polygerrit-ui/app/elements/settings/gr-gpg-editor/gr-gpg-editor.js
@@ -72,9 +72,8 @@
   }
 
   save() {
-    const promises = this._keysToRemove.map(key => {
-      this.$.restAPI.deleteAccountGPGKey(key.id);
-    });
+    const promises = this._keysToRemove
+        .map(key => this.$.restAPI.deleteAccountGPGKey(key.id));
 
     return Promise.all(promises).then(() => {
       this._keysToRemove = [];

polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor.js

diff --git a/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor.js b/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor.js
index d869128..9c819e9 100644
--- a/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor.js
+++ b/polygerrit-ui/app/elements/settings/gr-ssh-editor/gr-ssh-editor.js
@@ -63,9 +63,8 @@
   }
 
   save() {
-    const promises = this._keysToRemove.map(key => {
-      this.$.restAPI.deleteAccountSSHKey(key.seq);
-    });
+    const promises = this._keysToRemove
+        .map(key => this.$.restAPI.deleteAccountSSHKey(key.seq));
 
     return Promise.all(promises).then(() => {
       this._keysToRemove = [];