message: Fix divide by zero in procedural brick
  This changelist fixes a divide by zero in the Standard Surface procedural brick example material, removing a source of undefined behavior when comparing its rendering between shading languages.
diff: <input name="in1" type="float" nodename="node_divide_21" />
  <input name="in2" type="float" nodename="node_tiledimage_float_22" />
  </multiply>
  + <max name="node_max_1" type="float">
  + <input name="in1" type="float" nodename="node_tiledimage_float_10" />
  + <input name="in2" type="float" value="0.00001" />
  + </max>
  <divide name="node_divide_21" type="float">
  <input name="in1" type="float" interfacename="roughness_amount" />
  - <input name="in2" type="float" nodename="node_tiledimage_float_10" />
  + <input name="in2" type="float" nodename="node_max_1" />
  </divide>
  <mix name="node_mix_6" type="color3">
  <input name="fg" type="color3" interfacename="dirt_color" />
  