Doxygen: Enable client-based search engine

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/Doxyfile.gsm.in b/Doxyfile.gsm.in
index c4a837f..76c8f81 100644
--- a/Doxyfile.gsm.in
+++ b/Doxyfile.gsm.in
@@ -1141,7 +1141,7 @@
 # typically be disabled. For large projects the javascript based search engine
 # can be slow, then enabling SERVER_BASED_SEARCH may provide a better solution.
 
-SEARCHENGINE           = NO
+SEARCHENGINE           = YES
 
 # When the SERVER_BASED_SEARCH tag is enabled the search engine will be
 # implemented using a PHP enabled web server instead of at the web client