Fix spline ui zoom

I prevented the zoom from becoming too big or too small.

Signed-off-by: Ribhav Kaul <ribhavkaul@gmail.com>
Change-Id: Iaa617e13521980a37898a3974ff8bbd4b8c5c059
diff --git a/frc971/control_loops/python/path_edit.py b/frc971/control_loops/python/path_edit.py
index d743e0d..2e4e269 100755
--- a/frc971/control_loops/python/path_edit.py
+++ b/frc971/control_loops/python/path_edit.py
@@ -444,6 +444,12 @@
         # scale from point in field coordinates
         point = self.mousex, self.mousey
 
+        # This restricts the amount it can be scaled.
+        if self.transform.xx <= 0.4:
+            scale = max(scale, 1)
+        elif self.transform.xx >= 4:
+            scale = min(scale, 1)
+
         # move the origin to point
         self.transform.translate(point[0], point[1])