Fix for _is_solved is None

Author: alexandrutomescu

flowpaths/minflowdecompcycles.py

@@ -169,7 +169,6 @@ def __init__(
         self.solve_statistics = {}
         self._solution = None
         self._lowerbound_k = None
-        self._is_solved = None
 
         # Get the max flow value on an edge
         self.w_max = max(self.G.edges[edge][self.flow_attr]