sdk/python: Remove obsolete message in Makefile.

src/sdk/python/Makefile

@@ -5,8 +5,8 @@ MATURIN = maturin
 
 all:
 	$(MATURIN) build --release
-	@echo "You can install this wheel with make install"
+
 dev:
 	$(MATURIN) develop --release
 
-.PHONY: all
+.PHONY: all dev