MM-10020: avoid duplicating unique indexes (#8587)

* unit test TestGet(Search)Replica

This adds partial, testing-focused support for SQLite, as well as removing
some translated log messages that required initializing i18n just for
testing.

* avoid returning master twice when no replicas are configured

* remove duplicate indexes

* unit test GetAllConns

vendor/github.com/mattn/go-sqlite3/sqlite3_windows.go

@@ -0,0 +1,14 @@
+// Copyright (C) 2014 Yasuhiro Matsumoto <mattn.jp@gmail.com>.
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+// +build windows
+
+package sqlite3
+
+/*
+#cgo CFLAGS: -I. -fno-stack-check -fno-stack-protector -mno-stack-arg-probe
+#cgo windows,386 CFLAGS: -D_USE_32BIT_TIME_T
+#cgo LDFLAGS: -lmingwex -lmingw32
+*/
+import "C"