You can modify the resource file that’s providing the menu item to remove it (or move it elsewhere in the menu). However the SFTP
package specifies that it should always be installed as an unpacked package file, which means that whenever the package upgrades, your changes will be lost.
With that caveat, select View Package File
from the command palette and enter the text SFTP context menu
to filter the list of package files, then open SFTP/Context.sublime-menu
.
You can delete line 8 to remove the command, or move it to another place in the list of menu items to make it less likely for you to hit it. Once you save the file the changes are immediately applied.
Just remember that when the package updates, you need to do it again.