Fix color of 16px im-user-offline icon

It was supposed to match the other sizes by having a gray color,
accomplished by setting the opacity to 0.5, but this was not done.

BUG: 443658
FIXED-IN: 5.88

icons-dark/actions/16/im-user-offline.svg

@@ -6,7 +6,7 @@
       }
       </style>
   </defs>
- <path style="fill:currentColor;fill-opacity:1;stroke:none" 
+ <path style="fill:currentColor;fill-opacity:0.5;stroke:none"
        transform="translate(-421.71-531.79)"
        d="m429.71 533.79c-1.657 0-3 1.343-3 3 0 1.657 1.343 3 3 3 1.657 0 3-1.343 3-3 0-1.657-1.343-3-3-3m-2 2.5h4v1h-4zm2 4.5c-2.761 0-5 2.01-5 4.5.001.167.012.334.033.5h9.93c.023-.166.035-.333.037-.5 0-2.485-2.239-4.5-5-4.5m0 1c1.987.002 3.671 1.279 3.955 3h-7.91c.284-1.721 1.968-2.998 3.955-3"
        class="ColorScheme-Text"

icons/actions/16/im-user-offline.svg

@@ -6,7 +6,7 @@
       }
       </style>
   </defs>
- <path style="fill:currentColor;fill-opacity:1;stroke:none" 
+ <path style="fill:currentColor;fill-opacity:0.5;stroke:none"
        transform="translate(-421.71-531.79)"
        d="m429.71 533.79c-1.657 0-3 1.343-3 3 0 1.657 1.343 3 3 3 1.657 0 3-1.343 3-3 0-1.657-1.343-3-3-3m-2 2.5h4v1h-4zm2 4.5c-2.761 0-5 2.01-5 4.5.001.167.012.334.033.5h9.93c.023-.166.035-.333.037-.5 0-2.485-2.239-4.5-5-4.5m0 1c1.987.002 3.671 1.279 3.955 3h-7.91c.284-1.721 1.968-2.998 3.955-3"
        class="ColorScheme-Text"