Get 1.7.10 working with source remapping

Requires changing the 'core' version to 1.8 before compiling

settings.gradle

@@ -4,14 +4,16 @@ def coreMcVersion = f.exists() ? f.readLines().first() as int : 11302
 def jGuiVersions = []
 def replayModVersions = []
 if (gradle.gradleVersion.startsWith('3.')) {
-    if (coreMcVersion <= 10710) {
+    if (coreMcVersion <= 10800) { // allow 1.8 only to run The Preprocessor
         jGuiVersions += ['core']
         replayModVersions += ['core']
     }
     jGuiVersions += [
+            '1.8', // allow 1.8 only to run The Preprocessor
             '1.7.10',
     ]
     replayModVersions += [
+            '1.8', // allow 1.8 only to run The Preprocessor
             '1.7.10',
     ]
 } else {