Remove ref to framagit

INSTALL.md

@@ -19,7 +19,7 @@ brew install git cmake
 You can copy past the following code:
 
 ```sh
-git clone https://framagit.org/blaar/blc_core.git
+git clone https://promethe.u-cergy.fr/blibs/blc_core.git
 cd blc_core
 mkdir build
 cd build