Improve an error message in db_init().

If we cannot open a connection to the sqlite3 database, show the name of the
database we failed to access, and also hint at the fact that a likely reason
for the problem is a missing sqlite3 driver for libdbi.

Change-Id: If1c0026e882984b4358ce116ec4a7ad40340517c

src/libmsc/db.c

@@ -614,7 +614,8 @@ int db_init(const char *name)
 
 	conn = dbi_conn_new_r("sqlite3", inst);
 	if (conn == NULL) {
-		LOGP(DDB, LOGL_FATAL, "Failed to create connection.\n");
+		LOGP(DDB, LOGL_FATAL, "Failed to create database connection to sqlite3 db '%s'; "
+		    "Is the sqlite3 database driver for libdbi installed on this system?\n", name);
 		return 1;
 	}