BUG: boost user-config.jam written into incorrect directory

- mistake introduced by 11e3723f

makeCGAL

@@ -265,6 +265,10 @@ else
     # Absolute path for --libdir
 
     (
+        # Write user-config.jam into source directory
+        cd "$BOOST_SOURCE_DIR" || exit
+        export GIT_DIR="$PWD/.git" # Mask seeing our own git-repo
+
         # Configuration options:
         unset buildOpt
 
@@ -310,9 +314,6 @@ else
         # End of configuration options
         # ----------------------------
 
-        cd "$BOOST_SOURCE_DIR" || exit
-        export GIT_DIR="$PWD/.git" # Mask seeing our own git-repo
-
         rm -rf "$BOOST_ARCH_PATH"
 
         ./bootstrap.sh \