Fixed range defining error

app/api/tiler.py

@@ -125,8 +125,8 @@ class Metadata(TaskNestedView):
         if defined_range == '': defined_range = None
         try:
             expr, hrange = lookup_formula(formula, bands)
-            new_range = tuple(map(float, defined_range.split(",")[:2]))
             if defined_range is not None:
+                new_range = tuple(map(float, defined_range.split(",")[:2]))
                 #Validate rescaling range
                 if hrange is not None and (new_range[0] < hrange[0] or new_range[1] > hrange[1]):
                     pass