DbMigration: Check for mysql collation name whether to check 2.11 is migrated

library/Icinga/Application/Hook/DbMigrationHook.php

@@ -107,6 +107,35 @@ abstract class DbMigrationHook implements Countable
         return $result->column_type;
     }
 
+    /**
+     * Get the mysql collation name of the given column of the specified table
+     *
+     * @param Connection $conn
+     * @param string $table
+     * @param string $column
+     *
+     * @return ?string
+     */
+    public static function getColumnCollation(Connection $conn, string $table, string $column): ?string
+    {
+        if ($conn->getAdapter() instanceof Pgsql) {
+            return null;
+        }
+
+        $pdoStmt = $conn->prepexec(
+            'SELECT collation_name FROM information_schema.columns WHERE table_name = ? AND column_name = ?',
+            [$table, $column]
+        );
+
+        /** @var false|stdClass $result */
+        $result = $pdoStmt->fetch(PDO::FETCH_OBJ);
+        if ($result === false) {
+            return null;
+        }
+
+        return $result->collation_name;
+    }
+
     /**
      * Get statically provided descriptions of the individual migrate scripts
      *

library/Icinga/Application/ProvidedHook/DbMigration.php

@@ -52,7 +52,9 @@ class DbMigration extends DbMigrationHook
                 if (! $this->version) {
                     $this->version = '2.12.0';
                 }
-            } elseif (static::tableExists($conn, $schemaQuery->getModel()->getTableName())) {
+            } elseif (static::tableExists($conn, $schemaQuery->getModel()->getTableName())
+                || static::getColumnCollation($conn, 'icingaweb_user_preference', 'username') === 'utf8mb4_unicode_ci'
+            ) {
                 $this->version = '2.11.0';
             } elseif (static::tableExists($conn, 'icingaweb_rememberme')) {
                 $randomIvType = static::getColumnType($conn, 'icingaweb_rememberme', 'random_iv');