Camera attached to a Spring Arm jitters when put at a +90 or -90 degree angle on the Y axis.

When a camera attached to a spring arm is turned at a +90 or -90 degree angle in the Y Axis (can't go any further) and turned, it can jitter and cause visual issues.

Note: This occurs in the base ThirdPersonCharacter project as well, but certain springarm/camera positions show the issue more than others, hence the project given for reproduction

Regression?: Yes
This did not occur in 4.13.2-3172292+++UE4+Release-4.13
This does occur in 4.14.0-3195953+++UE4+Release-4.14

1. Download the attached project
2. Use the mouse to turn the camera to a 90 degree angle on the Y axis (facing directly down on top of the character)
3. Turn the camera while in that position
   Result: The camera jitters, not keeping a steady output
   Expected: The camera shouldn't jitter and should stay smooth.