Prevent NaN entries entering TPS insert

Affects issues:
- Fixed #1757

Plan/common/src/main/java/com/djrapitops/plan/gathering/domain/TPS.java

@@ -97,7 +97,7 @@ public class TPS implements DateHolder {
      * @return 0-100 double
      */
     public double getCPUUsage() {
-        return cpuUsage;
+        return Double.isNaN(cpuUsage) ? -1.0 : cpuUsage;
     }
 
     /**