With relative API stability in Godot 3.x, don't error when Godot bin
minor is less than pack file minor, warn instead. This is stop refusing
to run games that are built with HEAD and report higher minor version
than latest release.

Index: core/io/file_access_pack.cpp
--- core/io/file_access_pack.cpp.orig
+++ core/io/file_access_pack.cpp
@@ -211,10 +211,12 @@ bool PackedSourcePCK::try_open_pack(const String &p_pa
 		memdelete(f);
 		ERR_FAIL_V_MSG(false, "Pack version unsupported: " + itos(version) + ".");
 	}
-	if (ver_major > VERSION_MAJOR || (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR)) {
+	if (ver_major > VERSION_MAJOR) {
 		f->close();
 		memdelete(f);
 		ERR_FAIL_V_MSG(false, "Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor) + ".");
+	} else if (ver_major == VERSION_MAJOR && ver_minor > VERSION_MINOR) {
+		WARN_PRINT("Pack created with a newer version of the engine: " + itos(ver_major) + "." + itos(ver_minor) + ".");
 	}
 
 	for (int i = 0; i < 16; i++) {
