wscript: If pkg-config fails, look for local sqlite3 copy.

wscript

@@ -15,13 +15,11 @@ def configure(conf):
   conf.check_tool("compiler_cxx")
   conf.check_tool("node_addon")
   try:
-    conf.find_program('pkg-config', mandatory=True)
+    conf.check_cfg(package="sqlite3", args='--libs --cflags',
+                   uselib_store="SQLITE3", mandatory=True)
   except ConfigurationError:
     conf.check(lib="sqlite3", libpath=['/usr/local/lib', '/opt/local/lib'],
                uselib_store="SQLITE3", mandatory=True)
-  else:
-    conf.check_cfg(package="sqlite3", args='--libs --cflags',
-                   uselib_store="SQLITE3", mandatory=True)
 
 def build(bld):
   obj = bld.new_task_gen("cxx", "shlib", "node_addon")