The ornamental design for a columbariumdoor, as shown and described.
1. Columbarium door
2. Pair of columbarium doors
3. Set of three columbarium doors
1.1 : Perspective
1.2 : Top
1.3 : Front
1.4 : Right
1.5 : Back
1.6 : Bottom
2.1 : Perspective
2.2 : Top
2.3 : Front
2.4 : Right
2.5 : Back
2.6 : Bottom
3.1 : Perspective
3.2 : Top
3.3 : Front
3.4 : Right
3.5 : Bottom
3.6 : Back
1. The columbarium door, the pair of columbarium doors and the set of three columbarium doors for which protection is sought are shown in full lines, other portions of the columbariums are shown in dotted lines for context only and disclaimed; in the drawings: 1.1 is a perspective view of a columbarium door; 1.2 is a top plan view of the columbarium door being concealed; 1.3 is a front elevation view of the columbarium door; 1.4 is a right side elevation of the columbarium door being concealed; the other side elevation view is a mirror image and is not shown; 1.5 is a rear elevation view of the columbarium door being concealed; 1.6 is a bottom plan view of the columbarium door being concealed; 2.1 is a perspective view of a pair of columbarium doors according to a second variant; 2.2 is a top plan view of the pair of columbarium doors being concealed; 2.3 is a front elevation view of the pair of columbarium doors; 2.4 is a right side elevation view of the pair of columbarium doors being concealed; the other side elevation view is a mirror image and is not shown; 2.5 is a rear elevation of the pair of columbarium doors being concealed; 2.6 is a bottom plan view of the pair of columbarium doors being concealed; 3.1 is a perspective view of a set of three columbarium doors according to a third variant; 3.2 is a top plan view of the set of three columbarium doors being concealed; 3.3 is a front elevation of the set of three columbarium doors; 3.4 is a right side elevation of the set of three columbarium doors being concealed; the other side elevation view is a mirror image and is not shown; 3.5 is a rear elevation view of the set of three columbarium doors being concealed; and 3.6 is a bottom plan view of the set of three columbarium doors being concealed.