ipfs-http-client: fix compilation of tests

Wrong CMake variable was being used to enable them.

Small whitespace fix.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

libs/ipfs-http-client/Makefile

@@ -5,7 +5,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=ipfs-http-client
-PKG_RELEASE:=2
+PKG_RELEASE:=3
 
 PKG_MAINTAINER:=Leonid Esman <leonid.esman@gmail.com>
 PKG_LICENSE:=MIT
@@ -57,7 +57,7 @@ endef
 
 CMAKE_OPTIONS += \
 	-DBUILD_SHARED_LIBS=ON \
-	-DENABLE_TESTING=ON
+	-DBUILD_TESTING=ON
 
 define Package/libipfs-http-client/install
 	$(INSTALL_DIR) $(1)/usr/lib