comply the changes in ROPValue change in angrop

rex/exploit/technique.py

@@ -477,7 +477,7 @@ def _ip_overwrite_with_chain(self, chain, state=None, assert_next_ip_controlled=
             # if we can directly pivot to the symbolic region, do it
             # the assumption is the first value in the chain is a code address
             # it sounds like a reasonable assumption to me. But I can be wrong.
-            chain_constraints = [state.regs.sp == addr, state.regs.pc == chain._values[0][0]]
+            chain_constraints = [state.regs.sp == addr, state.regs.pc == chain._values[0].data]
             if state.solver.satisfiable(extra_constraints=chain_constraints):
                 chain_addr = addr
                 chain_cp = chain.copy()