fix(graph): Fix so that zoom works even when no data exists, fixes #5570

public/vendor/flot/jquery.flot.selection.js

@@ -162,8 +162,17 @@ The plugin allso adds the following methods to the plot object:
             if (!selection.show) return null;
             if (!selection.show) return null;
 
 
             var r = {}, c1 = selection.first, c2 = selection.second;
             var r = {}, c1 = selection.first, c2 = selection.second;
-            $.each(plot.getAxes(), function (name, axis) {
+            var axes = plot.getAxes();
+            // look if no axis is used
+            var noAxisInUse = true;
+            $.each(axes, function (name, axis) {
               if (axis.used) {
               if (axis.used) {
+                anyUsed = false;
+              }
+            })
+
+            $.each(axes, function (name, axis) {
+                if (axis.used || noAxisInUse) {
                     var p1 = axis.c2p(c1[axis.direction]), p2 = axis.c2p(c2[axis.direction]);
                     var p1 = axis.c2p(c1[axis.direction]), p2 = axis.c2p(c2[axis.direction]);
                     r[name] = { from: Math.min(p1, p2), to: Math.max(p1, p2) };
                     r[name] = { from: Math.min(p1, p2), to: Math.max(p1, p2) };
                 }
                 }