Fix xyplot affect all pipe #649

Author: yolain

py/nodes/pipe.py

@@ -490,7 +490,7 @@ def clean_values(values):
                    "output_individuals": output_individuals}
 
         if pipe is not None:
-            new_pipe = pipe
+            new_pipe = pipe.copy()
             new_pipe['loader_settings'] = {
                 **pipe['loader_settings'],
                 "xyplot": xy_plot
@@ -568,7 +568,7 @@ def plot(self, pipe, grid_spacing, output_individuals, flip_xy, X=None, Y=None,
             y_values = [""]
 
         if pipe is not None:
-            new_pipe = pipe
+            new_pipe = pipe.copy()
             positive = pipe["loader_settings"]["positive"] if "positive" in pipe["loader_settings"] else ""
             negative = pipe["loader_settings"]["negative"] if "negative" in pipe["loader_settings"] else ""