Adjust further columns

- calendarsubscriptions.lastmodified -> not null
- external_config.value -> allow null

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

apps/dav/lib/Migration/Version1004Date20170825134824.php

@@ -341,6 +341,12 @@ class Version1004Date20170825134824 extends SimpleMigrationStep {
 			]);
 			$table->setPrimaryKey(['id']);
 			$table->addUniqueIndex(['principaluri', 'uri'], 'calsub_index');
+		} else {
+			$table = $schema->getTable('calendarsubscriptions');
+			$table->changeColumn('lastmodified', [
+				'notnull' => false,
+				'unsigned' => true,
+			]);
 		}
 
 		if (!$schema->hasTable('schedulingobjects')) {

apps/files_external/lib/Migration/Version1011Date20200630192246.php

@@ -121,6 +121,12 @@ class Version1011Date20200630192246 extends SimpleMigrationStep {
 			$table->setPrimaryKey(['config_id']);
 			$table->addIndex(['mount_id'], 'config_mount');
 			$table->addUniqueIndex(['mount_id', 'key'], 'config_mount_key');
+		} else {
+			$table = $schema->getTable('external_config');
+			$table->changeColumn('value', [
+				'notnull' => false,
+				'length' => 4096,
+			]);
 		}
 
 		if (!$schema->hasTable('external_options')) {