The ornamental design for a shower gelcontainer, as shown and described.
FIG. 1 is a top and front perspective view of a shower gel container showing my present design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is an additional front elevational view thereof, the broken-line disclosure being for illustrative purposes only and forming no part of the claimed design.