fix elevation chart icon

style/_fa.scss

@@ -36,7 +36,7 @@ $fa-css-prefix: fa;
 .#{$fa-css-prefix}-track-main:before { content: fa-content($fa-var-hiking); }
 .#{$fa-css-prefix}-track-hitchhiking:before { content: fa-content($fa-var-car-side); }
 .#{$fa-css-prefix}-layers:before { content: fa-content($fa-var-layer-group); }
-.#{$fa-css-prefix}-elevation:before { content: fa-content($fa-var-chart-area); }
+.#{$fa-css-prefix}-elev-chart:before { content: fa-content($fa-var-chart-area); }
 .#{$fa-css-prefix}-message-in:before { content: fa-content($fa-var-shoe-prints); }
 .#{$fa-css-prefix}-distance:before { content: fa-content($fa-var-arrow-circle-right); }
 .#{$fa-css-prefix}-elevation:before { content: fa-content($fa-var-arrow-circle-up); }

style/_leaflet.scss

@@ -33,7 +33,7 @@ $stroke-width-axis : 2;
 	
 		.elevation-toggle {
 			@extend .control-icon;
-			@extend .fa-elevation;
+			@extend .fa-elev-chart;
 		}
 	}
 }