do not crash on repeated calls

src/api.c

@@ -39,6 +39,8 @@ api_rope(void)
     DBERR(sqlite3_finalize(remind_stmt));
     DBERR(sqlite3_finalize(set_repo_stmt));
     DBERR(sqlite3_finalize(get_nth_id_stmt));
+    DBERR(sqlite3_finalize(new_assignment_stmt));
+    DBERR(sqlite3_finalize(purge_assignments_stmt));
     sqlite3_close(connection);
 }
 
@@ -57,6 +59,7 @@ remind(char * who)
 	char * title;
 	char * desc;
 	char * repo;
+	DBERR(sqlite3_reset(remind_stmt));
 	DBERR(sqlite3_bind_text(remind_stmt, 1, who, -1, SQLITE_STATIC));
 	const int i = sqlite3_step(remind_stmt);
 	DBERR(i);
@@ -80,6 +83,7 @@ remind(char * who)
 DECL void
 set_repo(const char * const who, const char * const link)
 {
+	DBERR(sqlite3_reset(set_repo_stmt));
 	DBERR(sqlite3_bind_text(set_repo_stmt, 1, link, -1, SQLITE_STATIC));
 	DBERR(sqlite3_bind_text(set_repo_stmt, 2, who, -1, SQLITE_STATIC));
 	DBERR(sqlite3_step(set_repo_stmt));
@@ -153,6 +157,7 @@ get_project_count(){
 DECL int
 get_nth_id(const int i){
     int r;
+	DBERR(sqlite3_reset(get_nth_id_stmt));
     DBERR(sqlite3_bind_int(get_nth_id_stmt, 1, i));
     DBERR(sqlite3_step(get_nth_id_stmt));
     r = sqlite3_column_int(get_nth_id_stmt, 0);
@@ -161,6 +166,7 @@ get_nth_id(const int i){
 
 DECL void
 new_assignment(const char * const who, const int project){
+	DBERR(sqlite3_reset(new_assignment_stmt));
     DBERR(sqlite3_bind_text(new_assignment_stmt, 1, who, -1, SQLITE_STATIC));
     DBERR(sqlite3_bind_int(new_assignment_stmt, 2, project));
     DBERR(sqlite3_step(new_assignment_stmt));