Fix compile warning (#2337)

Author: HeRaNO

lib/inc/drogon/HttpAppFramework.h

@@ -43,14 +43,14 @@
 #include <vector>
 #include <chrono>
 
-#if defined(__APPLE__) && defined(__MACH__)
-#if defined(__ENVIRONMENT_IPHONE_OS__) || \
-    defined(__IPHONE_OS_VERSION_MIN_REQUIRED)
+#if defined(__APPLE__) && defined(__MACH__) && \
+    (defined(__ENVIRONMENT_IPHONE_OS__) ||     \
+     defined(__IPHONE_OS_VERSION_MIN_REQUIRED))
 // iOS
 #define TARGET_OS_IOS 1
-#elif defined(__MAC_OS_X_VERSION_MIN_REQUIRED)
-// macOS
-#endif
+#else
+// not iOS
+#define TARGET_OS_IOS 0
 #endif
 
 namespace drogon

lib/src/StaticFileRouter.cc

@@ -44,7 +44,7 @@ void StaticFileRouter::init(const std::vector<trantor::EventLoop *> &ioLoops)
                    size_t i) {
             assert(i == ioLoops[i]->index());
             mapPtr = std::make_unique<CacheMap<std::string, char>>(ioLoops[i],
-                                                                   1.0,
+                                                                   1.0f,
                                                                    4,
                                                                    50);
         });