Adding correct include path for NSPR, since it has changed. Patch from cls, r=bryner.

security/coreconf/ruleset.mk

@@ -277,6 +277,8 @@ else
 endif
 endif
 
+INCLUDES	+= -I$(SOURCE_XP_DIR)/include/nspr
+
 ifdef SYSTEM_INCL_DIR
 	YOPT = -Y$(SYSTEM_INCL_DIR)
 endif