Upgrade pg dependency version to 6.1.2 (#7824)
Upgrade pg dependency version to 6.1.2 (#7824)

refs #7815

- resolve the authentication error in pg 4.1.1
daimaqiao/Ghost-Bridge,pollbox/ghostblog,daimaqiao/Ghost-Bridge,pollbox/ghostblog,klinker-apps/ghost,klinker-apps/ghost,daimaqiao/Ghost-Bridge