Inter limit fix

fixed (one-off) error with limit higher than 2 (solving #388 (closed))

saqc/lib/ts_operators.py

@@ -310,7 +310,7 @@ def interpolateNANs(
     else:
         gap_mask = (
             gap_mask.replace(True, np.nan)
-            .fillna(method="bfill", limit=inter_limit)
+            .fillna(method="bfill", limit=inter_limit-1)
             .replace(np.nan, True)
             .astype(bool)
         )