fix(ux): fixed panel json edit view

public/app/partials/edit_json.html

@@ -12,7 +12,7 @@
 
 	<div class="gf-box-body json-box-body">
 		<div class="gf-form">
-			<textarea ng-model="json" rows="20" spellcheck="false"></textarea>
+			<textarea class="gf-form-input" ng-model="json" rows="20" spellcheck="false"></textarea>
 		</div>
 
 		<div class="gf-form-button-row">

public/sass/components/_dashboard.scss

@@ -288,8 +288,4 @@ div.flot-text {
 
 .json-box-body {
   min-height: 500px;
-  textarea {
-    width: 100%;
-    background-color: $gray-1;
-  }
 }