Tweak the way SkillCommands are constructed.

src/main/java/com/gmail/nossr50/commands/skills/AcrobaticsCommand.java

@@ -13,8 +13,8 @@ public class AcrobaticsCommand extends SkillCommand {
     private boolean canRoll;
     private boolean canGracefulRoll;
 
-    public AcrobaticsCommand(SkillType skill) {
-        super(skill);
+    public AcrobaticsCommand() {
+        super(SkillType.ACROBATICS);
     }
 
     @Override

src/main/java/com/gmail/nossr50/mcMMO.java

@@ -1,7 +1,6 @@
 package com.gmail.nossr50;
 
 import com.gmail.nossr50.datatypes.PlayerProfile;
-import com.gmail.nossr50.datatypes.SkillType;
 import com.gmail.nossr50.commands.skills.*;
 import com.gmail.nossr50.commands.spout.*;
 import com.gmail.nossr50.commands.mc.*;
@@ -285,7 +284,7 @@ public class mcMMO extends JavaPlugin {
 
         //Register commands
         //Skills commands
-        getCommand("acrobatics").setExecutor(new AcrobaticsCommand(SkillType.ACROBATICS));
+        getCommand("acrobatics").setExecutor(new AcrobaticsCommand());
         getCommand("archery").setExecutor(new ArcheryCommand());
         getCommand("axes").setExecutor(new AxesCommand());
         getCommand("excavation").setExecutor(new ExcavationCommand());