contrails: disable depth test so exaggerated terrain does not hide them

vendor/clouds3d.js

@@ -6913,12 +6913,14 @@ window.clouds3dRender = function(target) {
                     gl.vertexAttribPointer(ctA.s, 1, gl.FLOAT, false, 28, 20);
                     gl.enableVertexAttribArray(ctA.p);
                     gl.vertexAttribPointer(ctA.p, 1, gl.FLOAT, false, 28, 24);
+                    gl.disable(gl.DEPTH_TEST);
                     gl.depthMask(false);
                     gl.enable(gl.BLEND);
                     gl.blendFunc(gl.SRC_ALPHA, gl.ONE_MINUS_SRC_ALPHA);
                     gl.drawArrays(gl.TRIANGLES, 0, ctVerts);
                     gl.disable(gl.BLEND);
                     gl.depthMask(true);
+                    gl.enable(gl.DEPTH_TEST);
                 }
             }
             // Diagnostic snapshot: how many aircraft are in range, how many