Fixed mismatch between expected and configuration name of property

Main Plugin/src/main/java/com/jaimemartz/playerbalancer/settings/props/features/BalancerProps.java

@@ -79,6 +79,7 @@ public class BalancerProps {
     public String toString() {
         return "BalancerProps{" +
                 "principalSectionName='" + principalSectionName + '\'' +
+                ", defaultPrincipal=" + defaultPrincipal +
                 ", dummySectionNames=" + dummySectionNames +
                 ", reiterativeSectionNames=" + reiterativeSectionNames +
                 ", sectionProps=" + sectionProps +

Main Plugin/src/main/resources/default.conf

@@ -103,7 +103,7 @@ features {
 
     # When a player is not in any section, the player will go to the principal section
     # This affects both the fallback command and kick handler features
-    fallback-principal=true
+    default-principal=true
 
     # Dummy sections can have servers from other non-dummy sections
     # When a player connects to a dummy section, nothing will happen