Question [Q] Conflicting Post all over the net + Question

Ok the galaxy s4 active SGH-I537 are all the bootloaders locked or not as i have read some post here and else where that say some are and others are not when I go into Odin Mode i get

Odin Mode
Product Name: SGH-I537
Current Binary: Samsung Offical
System Status: Offical
Knox Kernel Lock: 0x0
Knox Warrenty Void: 0x0
Write Protection: Enable
eMC Burst Mode enabled

Now judging by reading this i am assuming that it is locked just looking for confirmation. The Reason I ask is i am wanting to dual boot the Phone with this For ubuntu touch although it says i need to have an unlocked phone and rooted which mine is rooted however they do not specifiy whether or not the mean sim unlocked or bootloader unlocked and i am going to take a shot in the dark and say they are meaning bootloader unlocked. if so would there be a possability to load the dual boot under safestrap ?

Samsung Galaxy Note i717D
HTC Inspire - IMM76+Ascension-v2.0 ( Retired )
T-Mobile MyTouch 3G - 2.2.1 CL300801-release-keys ( Retired )
Motorola Xoom - Team Eos Jr003L Nightly 137 ( Retired )