Fix crash after latest changes

Signed-off-by: falkTX <falktx@falktx.com>

source/modules/water/text/String.cpp

@@ -241,9 +241,7 @@ void String::clear() noexcept
 
 String& String::operator= (const String& other) noexcept
 {
-    StringHolder::retain (other.text);
-    std::swap(text.data, const_cast<CharPointer_UTF8&>(other.text).data);
-    StringHolder::release (other.text);
+    swapWith(const_cast<String&>(other));
     return *this;
 }