Don't build miniglog unconditionally as a static library
Don't build miniglog unconditionally as a static library

This is only needed on Windows because of lacking dllexport's.

Change-Id: I7ee4b3fd640d5870af2a73d7bfa6ccc8356b2fa0

kartikkumar/ceres-solver,timfel/ceres-bin,DougFirErickson/ceres-solver,stonier/ceres_solver,timfel/ceres-bin,kartikkumar/ceres-solver,whuaegeanse/ceres-solver,entylop/ceres-solver,stonier/ceres_solver,entylop/ceres-solver,kartikkumar/ceres-solver,stonier/ceres_solver,DougFirErickson/ceres-solver,ysonggit/ceres-solver,timfel/ceres-bin,whuaegeanse/ceres-solver,entylop/ceres-solver,ysonggit/ceres-solver,stonier/ceres_solver,ysonggit/ceres-solver,timfel/ceres-bin,whuaegeanse/ceres-solver,kartikkumar/ceres-solver,DougFirErickson/ceres-solver,whuaegeanse/ceres-solver,entylop/ceres-solver,ysonggit/ceres-solver,DougFirErickson/ceres-solver