Fix docgen as now warning are treated as error

dac4da86 · Frederic Bastien · 62d5cbeb · dac4da86
--- a/doc/library/sandbox/index.txt
+++ b/doc/library/sandbox/index.txt
@@ -18,4 +18,3 @@
    linalg
    neighbours
    rng_mrg
-    blocksparse