ArgumentOutOfRangeException Bugfix

MessageDeserializer.cs::Read(out string value) threw an error as soon as NaN values were present in the points of the mesh.
Zero values were therefore given and one was subtracted from them due to ROS2 conditions.
This resulted in negative becoming in a counting variable

com.unity.robotics.ros-tcp-connector/Runtime/MessageGeneration/MessageDeserializer.cs

@@ -138,7 +138,7 @@ public void Read(out string value)
             value = System.Text.Encoding.UTF8.GetString(data, offset, length);
 #else
             // ROS2 strings have a null byte at the end
-            value = System.Text.Encoding.UTF8.GetString(data, offset, length - 1);
+            value = System.Text.Encoding.UTF8.GetString(data, offset, Math.Max(0, length - 1));
 #endif
             offset += length;
         }