The ornamental design for a toiletbaseshield, as shown and described.
FIG. 1 is a front view of the toilet base shield.
FIG. 2 is a rear view of the toilet base shield.
FIG. 3 is a top view of the toilet base shield.
FIG. 4 is a bottom view of the toilet base shield.
FIG. 5 is a right end view of the toilet base shield.
FIG. 6 is a left end view of the toilet base shield; and,
FIG. 7 is a perspective view of the toilet base shield in the environment with which it is used, with phantom lines indicating a toilet which is within a proximity of the toilet base shield.