Changed RLGL_VERSION from "4.5" to "5.0 (#3914)

Line 110 of file rlgl.h is the one in question.

src/rlgl.h

@@ -107,7 +107,7 @@
 #ifndef RLGL_H
 #define RLGL_H
 
-#define RLGL_VERSION  "4.5"
+#define RLGL_VERSION  "5.0"
 
 // Function specifiers in case library is build/used as a shared library
 // NOTE: Microsoft specifiers to tell compiler that symbols are imported/exported from a .dll