space() now returns a point with NaNs instead of the original position when it can't find free space

src/level/robotmain.cpp

@@ -4154,6 +4154,11 @@ bool CRobotMain::FreeSpace(Math::Vector &center, float minRadius, float maxRadiu
             }
         }
     }
+
+    float nan = std::nanf("");
+
+    center = Math::Vector{ nan, nan, nan };
+
     return false;
 }