util/conf/GeneralPreferences: Fix typo.

Author: paulosousadias

src/java/pt/lsts/neptus/util/conf/GeneralPreferences.java

@@ -316,7 +316,7 @@ public class GeneralPreferences implements PropertiesProvider {
     @NeptusProperty(name = "Preferred Z Units Array", category = "Z Value", userLevel = LEVEL.ADVANCED, 
             editable = false, rendererClass = ArrayAsStringRenderer.class,
             description = "This lists the valid Z units to show. This can be override by the per vehicle settings. "
-                    + "Leeave it empty for no restrictions.")
+                    + "Leave it empty for no restrictions.")
     public static ManeuverLocation.Z_UNITS[] validZUnits = {};
 
     // -------------------------------------------------------------------------