Remove duplicate options and dependencies from respective variables

Duplicate options e.g. "+FOO +FOO" was causing the wanted and remote
options comparison to fail, causing poudriere to build packages
unnecessarily.

Duplicate dependencies e.g. "foo/bar foo/bar" was causing the wanted
and remote deps comparison to fail, causing poudriere to skip packages.

src/share/poudriere/common.sh

@@ -3679,7 +3679,7 @@ download_from_repo_check_pkg() {
 	    $1 == pkgbase && $3 == "off" {print "-"$2;printed=1}
 	    $1 != pkgbase && printed == 1 {exit}
 	    ' \
-	    "${remote_all_options}" | sort -k1.2 | paste -s -d ' ' -)
+	    "${remote_all_options}" | sort -k1.2 -u | paste -s -d ' ' -)
 
 	shash_get pkgname-options "${pkgname}" selected_options || \
 	    selected_options=
@@ -3705,7 +3705,8 @@ download_from_repo_check_pkg() {
 	    $1 == pkgbase {print $2;printed=1}
 	    $1 != pkgbase && printed == 1 {exit}
 	    ' \
-	    "${remote_all_deps}" | sort | paste -s -d ' ' -)
+	    "${remote_all_deps}" | sort -u | paste -s -d ' ' -)
+
 	case "${local_deps}" in
 	${remote_deps}) ;;
 	*)