Revert "Fixed the ifdef checks"

This reverts commit fc99d0c.

Author: cbeiraod

hdr/sqlite_modern_cpp.h

@@ -30,20 +30,16 @@
   template<class T>
   using optional = std::optional<T>;
   #define MODERN_SQLITE_OPTIONAL_SUPPORT
-#elif __has_include(<experimental/optional>)
-  #ifdef _MODERN_SQLITE_EXPERIMENTAL_OPTIONAL_SUPPORT
-    #include <experimental/optional>
-    template<class T>
-    using optional = std::experimental::optional<T>;
-    #define MODERN_SQLITE_OPTIONAL_SUPPORT
-  #endif
-#else
-  #ifdef _MODERN_SQLITE_BOOST_OPTIONAL_SUPPORT
-    #include <boost/optional.hpp>
-    template<class T>
-    using optional = boost::optional<T>;
-    #define MODERN_SQLITE_OPTIONAL_SUPPORT
-  #endif
+#elif _MODERN_SQLITE_EXPERIMENTAL_OPTIONAL_SUPPORT && __has_include(<experimental/optional>)
+  #include <experimental/optional>
+  template<class T>
+  using optional = std::experimental::optional<T>;
+  #define MODERN_SQLITE_OPTIONAL_SUPPORT
+#elif _MODERN_SQLITE_BOOST_OPTIONAL_SUPPORT
+  #include <boost/optional.hpp>
+  template<class T>
+  using optional = boost::optional<T>;
+  #define MODERN_SQLITE_OPTIONAL_SUPPORT
 #endif
 
 #include <sqlite3.h>