replaced git: by https:

README.md

@@ -47,10 +47,11 @@ $ make install
 
 # Clone open62541
 ```bash
-$ git clone git://github.com/acplt/open62541.git
+$ git clone https://github.com/acplt/open62541.git
 ```
 
-# Building (autogen.sh only first time)
+# Building 
+* use autogen.sh only first time and whenever aclocal.m4 or configure.ac were modified
 ```bash
 $ cd open62541
 $ ./autogen.sh