Fix output message

Author: rubenmromero

git_matrix.sh

@@ -78,7 +78,7 @@ then
  done
  if [[ $UPDATE_APPL != $1 ]]
  then
- $ECHO "\nThe '$1' application submodule specified as input param not exists in the project"
+ $ECHO "\nThe '$1' application submodule specified as input param does not exist in the project"
  print_exec_mode
  exit 1
  fi