You could expand your convergence tolerance in the Building object:
Building, Project, !- Name 315, !- North Axis {deg} Suburbs, !- Terrain 0.02, !- Loads Convergence Tolerance Value
0.4, !- Temperature Convergence Tolerance Value {deltaC} FullExterior, !- Solar Distribution 40, !- Maximum Number of Warmup Days 6; !- Minimum Number of Warmup Days
This will get rid of the warning, which should be safe to ignore anyhow.
Alternatively, you could increase the number of warmup days which should allow your simulation to converge to a tighter tolerance.