Increase bcast2,bcast3 timelimit to 13 mins.

Nightly testing reported timeout on octopus with 12 timelimit. Each of
them took 12:05 ~ 12:10 mins.

test/mpi/coll/testlist

@@ -35,8 +35,8 @@ bcasttest 10
 bcast2 4
 # More that 8 processes are required to get bcast to switch to the long
 # msg algorithm (see coll definitions in mpiimpl.h)
-bcast2 10 timeLimit=720
-bcast3 10 timeLimit=720
+bcast2 10 timeLimit=780
+bcast3 10 timeLimit=780
 bcastzerotype 1
 bcastzerotype 4
 bcastzerotype 5