Remove loading gif

Instead of an external gif, use the BusyIndicator that exists in the ActionButton.

plugins/Toolbox/resources/images/loading.svg

@@ -1 +0,0 @@
-<svg width="200px" height="200px" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="xMidYMid" class="lds-rolling" style="animation-play-state: running; animation-delay: 0s; background-image: none; background-position: initial initial; background-repeat: initial initial;"><circle cx="50" cy="50" fill="none" ng-attr-stroke="{{config.color}}" ng-attr-stroke-width="{{config.width}}" ng-attr-r="{{config.radius}}" ng-attr-stroke-dasharray="{{config.dasharray}}" stroke="#0CA9E3" stroke-width="13" r="43" stroke-dasharray="202.63272615654165 69.54424205218055" style="animation-play-state: running; animation-delay: 0s;"><animateTransform attributeName="transform" type="rotate" calcMode="linear" values="0 50 50;360 50 50" keyTimes="0;1" dur="1s" begin="0s" repeatCount="indefinite" style="animation-play-state: running; animation-delay: 0s;"></animateTransform></circle></svg>

plugins/Toolbox/resources/qml/ToolboxProgressButton.qml

@@ -62,17 +62,6 @@ Item
                 readyAction()
             }
         }
-    }
-
-    AnimatedImage
-    {
-        id: loader
-        visible: active
-        source: visible ? "../images/loading.gif" : ""
-        width: UM.Theme.getSize("toolbox_loader").width
-        height: UM.Theme.getSize("toolbox_loader").height
-        anchors.right: button.left
-        anchors.rightMargin: UM.Theme.getSize("default_margin").width
-        anchors.verticalCenter: button.verticalCenter
+        busy: active
     }
 }

resources/qml/ActionButton.qml

@@ -130,5 +130,15 @@ Button
         height: parent.height
 
         visible: false
+
+        RotationAnimator
+        {
+            target: busyIndicator.contentItem
+            running: busyIndicator.visible && busyIndicator.running
+            from: 0
+            to: 360
+            loops: Animation.Infinite
+            duration: 2500
+        }
     }
 }