Add fallback to method not in older Spigot versions

Author: PseudoKnight

src/main/java/com/laytonsmith/abstraction/bukkit/entities/BukkitMCHumanEntity.java

@@ -95,7 +95,12 @@ public void setCooldown(MCMaterial material, int ticks) {
 
 	@Override
 	public float getAttackCooldown() {
-		return he.getAttackCooldown();
+		try {
+			return he.getAttackCooldown();
+		} catch (NoSuchMethodError ex) {
+			// probably before 1.15.2
+			return 1.0f;
+		}
 	}
 
 	@Override

src/main/java/com/laytonsmith/core/functions/PlayerManagement.java

@@ -5603,7 +5603,8 @@ public Integer[] numArgs() {
 		@Override
 		public String docs() {
 			return "double {[player]} Gets the charge value of the player's attack cooldown. This is a "
-					+ " double with range 0.0-1.0 inclusive. 1.0 is fully charged, while 0.0 is no charge.";
+					+ " double with range 0.0-1.0 inclusive. 1.0 is fully charged, while 0.0 is no charge."
+					+ " (Spigot versions prior to 1.15.2 will always return 1.0)";
 		}
 
 		@Override