Remove unneeded spacing from an error message

Author: alexeyr

node_package/src/ReactOnRails.client.ts

@@ -26,13 +26,10 @@ if (ctx === undefined) {
 
 if (ctx.ReactOnRails !== undefined) {
   /* eslint-disable @typescript-eslint/no-base-to-string -- Window and Global both have useful toString() */
-  throw new Error(`
-    The ReactOnRails value exists in the ${ctx} scope, it may not be safe to overwrite it.
-
-    This could be caused by setting Webpack's optimization.runtimeChunk to "true" or "multiple," rather than "single." Check your Webpack configuration.
-
-    Read more at https://github.com/shakacode/react_on_rails/issues/1558.
-  `);
+  throw new Error(`\
+The ReactOnRails value exists in the ${ctx} scope, it may not be safe to overwrite it.
+This could be caused by setting Webpack's optimization.runtimeChunk to "true" or "multiple," rather than "single."
+Check your Webpack configuration. Read more at https://github.com/shakacode/react_on_rails/issues/1558.`);
   /* eslint-enable @typescript-eslint/no-base-to-string */
 }