UNITED STATES — Women journalists have entered 2019 already at a disadvantage. Last year, 2018 was singled out as the worst year for journalists around the world. More than half a dozen women journalists were killed, and hundreds detained.Journalists already have quite a number of problems to tackle in the field, and many governments are either continuing to — or beginning to — make matters worse. President Donald J. Trump has been known to trivialize the work of journalists, but his special focus on women has been lost to no one.