Limit parallel script processing thread pool to 4 by default (#1764)

* Defaults: Limit script threads to 2 by default

* Defaults: Limit script threads to 4 by default

* Tweak logic to align better with negative values

* Fix tweak

* Revert "Tweak logic to align better with negative values"

This reverts commit 33df70d.

src/init.cpp

@@ -1476,6 +1476,10 @@ bool AppInitMain(InitInterfaces& interfaces)
         // -par=0 means autodetect (number of cores - 1 script threads)
         // -par=-n means "leave n cores free" (number of cores - n - 1 script threads)
         script_threads += GetNumCores();
+        // DeFiChain specific:
+        // Set this to a max value, since most custom TXs don't utilize this unfortunately 
+        // and is just a waste of resources. 
+        script_threads = std::min(script_threads, 4);
     }
 
     // Subtract 1 because the main thread counts towards the par threads