[headers] fixes headers of some ML files

ptests/ptests.ml

ptests/wtests.ml

src/init/impl_cmdline/gui_init.ml

src/plugins/callgraph/callgraph.ml

src/plugins/callgraph/gui/graph.dgraph.ml

src/plugins/callgraph/gui/graph.gtk.ml

src/plugins/e-acsl/E_ACSL.ml

src/plugins/e-acsl/src/local_config.ml

src/plugins/gui/debug_manager.ko.ml

src/plugins/loop_analysis/LoopAnalysis.ml

src/plugins/markdown-report/Mardown_report.ml

src/plugins/metrics/metrics.ml

src/plugins/pdg/Pdg.ml

src/plugins/reduc/reduc.ml

src/plugins/report/Report.ml

src/plugins/rte/RteGen.ml

src/plugins/scope/scope.ml

src/plugins/server/server_zmq.ko.ml

src/plugins/sparecode/Sparecode.ml

src/plugins/users/Users.ml