Consider fft2d license as permissive

```
Copyright
    Copyright(C) 1997,2001 Takuya OOURA (email: ooura@kurims.kyoto-u.ac.jp).
    You may use, copy, modify this code for any purpose and
    without fee. You may distribute this ORIGINAL package.
```

build/conf/license.conf

@@ -66,7 +66,6 @@ LICENSES_UNATTRIBUTED= \
     CDDL \
     CECILL-B \
     ClArtistic \
-    Custom-fft2d \
     DOC \
     DSO-1.1 \
     Elastic-License-2.0 \
@@ -274,9 +273,10 @@ LICENSES_PERMISSIVE= \
     Cmu-Computing-Services \
     CUP-Parser \
     curl \
+    Custom-fft2d \
+    Custom-openldap \
     Custom-punycode \
     Custom-wcwidth \
-    Custom-openldap \
     EDL-1.0 \
     Facebook-SDK \
     FDK \