MT#60094 Add "no-trailing-spaces" rule in linter

Add "no-trailing-spaces" rule to prevent unnecessary extra spaces.

Change-Id: I639e74752925c9331418442550e486f9946d7045

.eslintrc.js

@@ -63,7 +63,7 @@ module.exports = {
         'import/no-extraneous-dependencies': 'off',
         'prefer-promise-reject-errors': 'off',
         'no-tabs': 'error',
-        'no-trailing-spaces': 'off',
+        'no-trailing-spaces': 'error',
         // allow debugger during development only
         'no-debugger': process.env.NODE_ENV === 'production' ? 'error' : 'off',
         'indent': ['error', 4],

src/store/call/mutations.js

@@ -121,7 +121,6 @@ export default {
     setLocalOnHold (state, value) {
         state.localOnHold = value
     },
-    
     setRemoteOnHold (state, value) {
         state.remoteOnHold = value
     },
@@ -133,5 +132,4 @@ export default {
             state.transferEnabled = false
         }
     }
-    
 }