pptp-linux: fix parallel build

Fix parallel build issue

The config.h header file must be created before being used to build

source files that include it, especially version.c. In order for this

to happen even in highly-parallel builds, we add a dependency of all

object files on config.h, in order to ensure it gets generated before

make attempts to build the object files.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

Index: b/Makefile

===================================================================

--- a/Makefile

+++ b/Makefile

@@ -37,6 +37,8 @@

 all: config.h $(PPTP_BIN) pptpsetup.8

+$(PPTP_OBJS): config.h

+

 $(PPTP_BIN): $(PPTP_OBJS) $(PPTP_DEPS)

 	$(CC) -o $(PPTP_BIN) $(PPTP_OBJS) $(LDFLAGS) $(LIBS)