Revert "pptp-linux: fix build with high BR2_JLEVEL settings"

This reverts commit ffc4afe084a76e7246bd373c73b706f512a86c2b.

Commit from 2012 "ffc4afe084 pptp-linux: fix build with high BR2_JLEVEL
settings" added <pkg>_MAKE to a generic package, but the generic infra
does not take this symbol into account.

The build issue was fixed in 2013 with commit "a5b8081b89 pptp-linux:
fix parallel build" by adding a patch file.

So drop the bogus PPTP_LINUX_MAKE.

Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/pptp-linux/pptp-linux.mk

@@ -7,7 +7,6 @@
 PPTP_LINUX_VERSION = 1.10.0
 PPTP_LINUX_SITE = http://downloads.sourceforge.net/project/pptpclient/pptp/pptp-$(PPTP_LINUX_VERSION)
 PPTP_LINUX_SOURCE = pptp-$(PPTP_LINUX_VERSION).tar.gz
-PPTP_LINUX_MAKE = $(MAKE1)
 PPTP_LINUX_LICENSE = GPL-2.0+
 PPTP_LINUX_LICENSE_FILES = COPYING