fixed lack of raising error in the self assign commands even tho the converts return nothing.

Roxbot/cogs/selfassign.py

@@ -43,7 +43,7 @@ class SelfAssign():
 		"""
 		if role is None:
 			raise commands.BadArgument
-		
+
 		settings = gs.get(ctx.guild)
 		if not settings.self_assign["enabled"]:
 			embed = discord.Embed(colour=discord.Colour(self.embed_colour),
@@ -72,7 +72,7 @@ class SelfAssign():
 		"""
 		if role is None:
 			raise commands.BadArgument
-
+	
 		settings = gs.get(ctx.guild)
 		if not settings.self_assign["enabled"]:
 			embed = discord.Embed(colour=discord.Colour(self.embed_colour),