Fix incorrect bool parsing (#4991)

For example `--json=false` would still print JSON.

Went through all usage, and I think I covered them all.

cmd/admin-replicate-remove.go

@@ -95,15 +95,15 @@ func (i srRemoveStatus) String() string {
 func checkAdminReplicateRemoveSyntax(ctx *cli.Context) {
 	// Check argument count
 	argsNr := len(ctx.Args())
-	if ctx.IsSet("all") && argsNr > 1 {
+	if ctx.Bool("all") && argsNr > 1 {
 		fatalIf(errInvalidArgument().Trace(ctx.Args().Tail()...),
 			"")
 	}
-	if argsNr < 2 && !ctx.IsSet("all") {
+	if argsNr < 2 && !ctx.Bool("all") {
 		fatalIf(errInvalidArgument().Trace(ctx.Args().Tail()...),
 			"Need at least two arguments to remove command.")
 	}
-	if !ctx.IsSet("force") {
+	if !ctx.Bool("force") {
 		fatalIf(errDummy().Trace(),
 			"Site removal requires --force flag. This operation is *IRREVERSIBLE*. Please review carefully before performing this *DANGEROUS* operation.")
 	}