docs(dependency-injection): remove duplicated 'and' word (#3341)

Author: AlexanderLukin

Diff for: public/docs/ts/latest/cookbook/dependency-injection.jade

@@ -137,7 +137,7 @@ figure.image-display
   The `LoggerService` doesn't depend on anything. The logger would work if we omitted `@Injectable()`
   and the generated code would be slightly smaller. 
 
-  But the service would break the moment we gave it a dependency and we'd have to go back and
+  But the service would break the moment we gave it a dependency and we'd have to go back
   and add `@Injectable()` to fix it. We add `@Injectable()` from the start for the sake of consistency and to avoid future pain.
 
 .alert.is-helpful