[Reactor] Avoid a segfault when using phases with no Kinetics

include/cantera/zeroD/Reactor.h

@@ -78,6 +78,8 @@ public:
         m_kin = &kin;
         if (m_kin->nReactions() == 0) {
             disableChemistry();
+        } else {
+            enableChemistry();
         }
     }
 

interfaces/cython/cantera/reactor.pyx

@@ -165,7 +165,8 @@ cdef class Reactor(ReactorBase):
     def insert(self, _SolutionBase solution):
         ReactorBase.insert(self, solution)
         self._kinetics = solution
-        self.reactor.setKineticsMgr(deref(solution.kinetics))
+        if solution.kinetics != NULL:
+            self.reactor.setKineticsMgr(deref(solution.kinetics))
 
     property kinetics:
         """

src/zeroD/Reactor.cpp

@@ -23,7 +23,7 @@ Reactor::Reactor() : ReactorBase(),
     m_kin(0),
     m_vdot(0.0),
     m_Q(0.0),
-    m_chem(true),
+    m_chem(false),
     m_energy(true),
     m_nsens(npos)
 {}