more RSClient refactoring

runescape-api/src/main/java/net/runelite/rs/api/RSClient.java

@@ -978,7 +978,7 @@ public interface RSClient extends RSGameShell, Client
 	@Import("Rasterizer2D_drawVerticalLine")
 	void rasterizerDrawVerticalLine(int x, int y, int h, int rgb);
 
-	@Import("drawGradient")
+	@Import("Rasterizer2D_drawGradient")
 	void rasterizerDrawGradient(int x, int y, int w, int h, int rgbTop, int rgbBottom);
 
 	@Import("Rasterizer2D_fillRectangleAlpha")