Add OpenVPN to the build

CM used to build OpenVPN but the change was lost in
e1f3738e7c48be442c2a046a3e8dc92c56542f66. This adds it back.

Change-Id: I4c7e2c638a29ec184ff67ac096bf08cd2e126cab
diff --git a/config/common.mk b/config/common.mk
index bd1f392..add0032 100644
--- a/config/common.mk
+++ b/config/common.mk
@@ -104,6 +104,10 @@
     libcyanogen-dsp \
     audio_effects.conf
 
+# Extra tools in CM
+PRODUCT_PACKAGES += \
+    openvpn
+
 PRODUCT_PACKAGE_OVERLAYS += vendor/cm/overlay/dictionaries
 PRODUCT_PACKAGE_OVERLAYS += vendor/cm/overlay/common