CR: use :- to fallback to origin

Co-authored-by: Jordan Harband <ljharb@gmail.com>

install.sh

@@ -141,9 +141,7 @@ install_nvm_from_git() {
 
   local remote
   remote="$(git config --global clone.defaultRemoteName || true)"
-  if [ -z "$remote" ]; then
-      remote=origin
-  fi
+  remote="${remote:-origin}"
   local fetch_error
   if [ -d "$INSTALL_DIR/.git" ]; then
     # Updating repo
@@ -151,7 +149,7 @@ install_nvm_from_git() {
     command printf '\r=> '
     fetch_error="Failed to update nvm with $NVM_VERSION, run 'git fetch' in $INSTALL_DIR yourself."
   else
-    fetch_error="Failed to fetch $remote with $NVM_VERSION. Please report this!"
+    fetch_error="Failed to fetch ${remote} with ${NVM_VERSION}. Please report this!"
     nvm_echo "=> Downloading nvm from git to '$INSTALL_DIR'"
     command printf '\r=> '
     mkdir -p "${INSTALL_DIR}"