The ornamental design for a door-mounted refrigerator, as shown and described.
1. Door-mounted refrigerator
1.1 : Perspective
1.2 : Front
1.3 : Back
1.4 : Left
1.5 : Right
1.6 : Top
1.7 : Bottom
1.8 : Perspective
1.9 : Front
1.10 : Back
1.11 : Left
1.12 : Right
1.13 : Top
1.14 : Bottom
Reproductions 1.1 to 1.7 indicate a normal state of the claimed design; reproductions 1.8 to 1.14 indicate a state of the door that is changed to the state of ‘see-through door’ according to a signal from the sensor that has detected user's approach or touch; broken lines illustrate environmental condition only and form no part of the claimed design.