Fix SnapGrid is almost invisble in light theme

(cherry picked from commit 926e22d2ab100021a1c26585ed779842dd2c6086)

editor/icons/SnapGrid.svg

@@ -1 +1 @@
-<svg height="16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="M2 0v2H0v1h2v4H0v1h2v4H0v1h2v2h1v-2h3v-1H3V8h4l1-1V3h4v3h1V3h2V2h-2V0h-1v2H8V0H7v2H3V0zm1 3h4v4H3zm4 10v2h2v-2zm6 0v2h2v-2z" fill="#def"/><path d="M7 13h2v-2a2 2 0 0 1 4 0v2h2v-2a4 4 0 0 0-8 0z" fill="#def" fill-opacity=".8"/></svg>
+<svg height="16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="M2 0v2H0v1h2v4H0v1h2v4H0v1h2v2h1v-2h3v-1H3V8h4l1-1V3h4v3h1V3h2V2h-2V0h-1v2H8V0H7v2H3V0zm1 3h4v4H3zm4 10v2h2v-2zm6 0v2h2v-2z" fill="#e0e0e0"/><path d="M7 13h2v-2a2 2 0 0 1 4 0v2h2v-2a4 4 0 0 0-8 0z" fill="#e0e0e0" fill-opacity=".8"/></svg>