Fixed PHP 5.6 and 7.0 compatibility

Author: mahagr

Blueprints/src/BlueprintForm.php

@@ -348,7 +348,7 @@ protected function deepMerge(array $a, array $b)
             unset($bref_stack[key($bref_stack)]);
 
             foreach ($head as $key => $value) {
-                if (is_string($key) && str_contains($key, '@')) {
+                if (is_string($key) && ('' === $key || false !== strpos($key, '@'))) {
                     // Remove @ from the start and the end. Key syntax `import@2` is supported to allow multiple operations of the same type.
                     $list = explode('-', (string)preg_replace('/^(@*)?([^@]+)(@\d*)?$/', '\2', $key), 2);
                     $action = array_shift($list);

CHANGELOG.md

@@ -1,3 +1,9 @@
+# v1.6.1
+## mm/dd/2022
+
+1. [](#bugfix)
+    * Fixed PHP 5.6 and 7.0 compatibility
+
 # v1.6.0
 ## 12/15/2021
 

composer.json

@@ -8,16 +8,9 @@
     "require": {
         "php": ">=5.6.0",
         "ext-json": "*",
-        "symfony/polyfill-php80": "^1.23",
-        "symfony/polyfill-php81": "^1.23",
-        "pimple/pimple": "~3.0",
-        "symfony/yaml": "^3.4|^4.0",
-        "symfony/event-dispatcher": "^3.4|^4.0"
-    },
-    "require-dev": {
-        "phpunit/phpunit": "^8.0",
-        "phpstan/phpstan": "^1.2",
-        "phpstan/phpstan-deprecation-rules": "^1.0"
+        "pimple/pimple": "^3.0",
+        "symfony/yaml": "^3.4|^4.0|^5.0",
+        "symfony/event-dispatcher": "^3.4|^4.0|^5.0"
     },
     "autoload": {
         "psr-4": {