wscript: Fix include path for config.h

config.h is generated in build/, that's "../" at compile time.

For the sake of completeness, here's the waf error:

[122/163] cxx: common/Jackdmp.cpp -> build/common/Jackdmp.cpp.1.o
In file included from ../common/Jackdmp.cpp:35:0:
../common/JackConstants.h:24:20: fatal error: config.h: No such file or directory
compilation terminated.
Waf: Leaving directory `/home/adi/jack2/build'
Build failed
 -> task in 'jackd' failed (exit status 1):
        {task 39469904: cxx Jackdmp.cpp -> Jackdmp.cpp.1.o}
['/usr/bin/g++', '-Wall', '-I/home/adi/jack2/build/linux', '-I/home/adi/jack2/linux', '-I/home/adi/jack2/build/posix', '-I/home/adi/jack2/posix', '-I/home/adi/jack2/build/common/jack', '-I/home/adi/jack2/common/jack', '-I/home/adi/jack2/build/common', '-I/home/adi/jack2/common', '-I/home/adi/jack2/build/dbus', '-I/home/adi/jack2/dbus', '-DHAVE_CONFIG_H', '-DSERVER_SIDE', '../common/Jackdmp.cpp', '-c', '-o', 'common/Jackdmp.cpp.1.o']

linux/wscript

@@ -21,7 +21,7 @@ def create_jack_driver_obj(bld, target, sources, uselib = None):
     #driver.defines = ['HAVE_CONFIG_H','SERVER_SIDE', 'HAVE_PPOLL']
     driver.defines = ['HAVE_CONFIG_H','SERVER_SIDE', 'HAVE_PPOLL', 'HAVE_TIMERFD']
 
-    driver.includes = ['.', '../linux', '../posix', '../common', '../common/jack', '../dbus']
+    driver.includes = ['.', '../linux', '../posix', '../common', '../common/jack', '../dbus', '../']
     driver.target = target
     driver.source = sources
     driver.install_path = '${ADDON_DIR}/'
@@ -34,7 +34,7 @@ def build(bld):
     if bld.env['BUILD_JACKD'] == True:
         jackd = bld.new_task_gen('cxx', 'program')
         jackd.features += 'cxx'
-        jackd.includes = ['../linux', '../posix', '../common/jack', '../common', '../dbus']
+        jackd.includes = ['../linux', '../posix', '../common/jack', '../common', '../dbus', '../']
         jackd.defines = ['HAVE_CONFIG_H','SERVER_SIDE']
         jackd.source = ['../common/Jackdmp.cpp']
     if bld.env['IS_LINUX'] and bld.env['BUILD_JACKDBUS']: