perspective: Allow empty text for getCanvasTextLocation

This is particularly useful for aligning text to a certain point such
that it would not be centered on that point, such as left or right
alignment.

runelite-api/src/main/java/net/runelite/api/Perspective.java

@@ -379,7 +379,7 @@ public class Perspective
 		@Nullable String text,
 		int zOffset)
 	{
-		if (text == null || "".equals(text))
+		if (text == null)
 		{
 			return null;
 		}