The ornamental design for a feedingbottlesterilizer, as shown and described.
FIG. 1 is a front right perspective view of the feeding bottle sterilizer;
FIG. 2 is a front left perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left view thereof where the right view is a mirror image;
FIG. 6 is a top view thereof; and,
FIG. 7 is a bottom view thereof.
The broken lines depict portions of the feeding bottle sterilizer that form no part of the claimed design; the broken lines form no part of the claimed design. The dash-dot broken lines define the bounds of the claimed design and form no part thereof.