Fix problems in the installation script

Fix typo in package name.
Properly handle checks for python.

autoinstall_framework.sh

@@ -250,7 +250,7 @@ check_prerequisites()
   check_file_exist /usr/include/openssl/ssl.h ssl-dev
   check_file_exist /usr/include/gsl/gsl_types.h gsl-dev
   check_file_exist /usr/include/tbb/tbb.h tbb-dev
-  check_file_exist /usr/include/xercesc/dom/DOM.hpp xecesc-dev
+  check_file_exist /usr/include/xercesc/dom/DOM.hpp xercesc-dev
   check_file_exist /usr/include/yaml-cpp/binary.h yaml-cpp
 
   check_file_exist /usr/bin/curl-config curl-dev
@@ -267,8 +267,11 @@ check_prerequisites()
     tmp=$(which python3-config)
     if [ $? -ne 0 ]; then
       nof_missing_packages=$((nof_missing_packages+1))
-      missing_packages="python-dev, $missing_packages"
+      missing_packages="python3-dev, $missing_packages"
     fi
+  else
+    nof_missing_packages=$((nof_missing_packages+1))
+    missing_packages="python-dev, $missing_packages"
   fi
 
   if [ $nof_missing_packages -ne 0 ]; then