Fix model title not being broadcast to all ranks

gprMax/mpi_model.py

@@ -58,6 +58,8 @@ class MPIModel(Model):
         return super().build_geometry()
 
     def _broadcast_model(self):
+        self.title = self.comm.bcast(self.title)
+
         self.nx = self.comm.bcast(self.nx)
         self.ny = self.comm.bcast(self.ny)
         self.nz = self.comm.bcast(self.nz)