removes the specific upsert query which is available on PSQL 9.5 only

… in favor of the generic way

fixes #15613 properly and overrides #16461

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

Author: blizzz

lib/private/DB/AdapterPgSql.php

@@ -36,16 +36,4 @@ public function fixupStatement($statement) {
 		return $statement;
 	}
 
-	/**
-	 * @suppress SqlInjectionChecker
-	 */
-	public function insertIgnoreConflict(string $table,array $values) : int {
-		$builder = $this->conn->getQueryBuilder();
-		$builder->insert($table);
-		foreach($values as $key => $value) {
-			$builder->setValue($key, $builder->createNamedParameter($value));
-		}
-		$queryString = $builder->getSQL() . ' ON CONFLICT DO NOTHING';
-		return $this->conn->executeUpdate($queryString, $builder->getParameters(), $builder->getParameterTypes());
-	}
 }

lib/private/legacy/util.php

@@ -978,9 +978,9 @@ public static function checkDatabaseVersion() {
 				$data = $result->fetchRow();
 				if (isset($data['server_version'])) {
 					$version = $data['server_version'];
-					if (version_compare($version, '9.5.0', '<')) {
+					if (version_compare($version, '9.0.0', '<')) {
 						$errors[] = array(
-							'error' => $l->t('PostgreSQL >= 9.5 required'),
+							'error' => $l->t('PostgreSQL >= 9 required'),
 							'hint' => $l->t('Please upgrade your database version')
 						);
 					}