[BUG] Fix whitespace in AccessTransformers causing setup to fail on 1.8.9

Author: hypherionmc

src/minecraft/kotlin/xyz/wagyourtail/unimined/internal/minecraft/patch/access/transformer/AccessTransformerMinecraftTransformer.kt

@@ -124,6 +124,15 @@ interface AccessTransformerMinecraftTransformer : AccessTransformerPatcher, Acce
         ).use {
             ATWriter.writeData(list, it::append)
         }
+
+        // Fix whitespaces in ATs that can cause forge to fail on 1.8.9+
+        if (!legacyATFormat) {
+            val lines = temp.bufferedReader().readLines()
+            temp.bufferedWriter().use {
+                    writer -> lines.filter { s -> !s.startsWith(" ") }.forEach { writer.write(it) }
+            }
+        }
+
         try {
             project.execOps.javaexec { spec ->
                 if (useToolchains) {