Small improvement

app/src/main/java/eu/faircode/email/FragmentOptionsMisc.java

@@ -1590,7 +1590,7 @@ public class FragmentOptionsMisc extends FragmentBase implements SharedPreferenc
         btnGC.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                Helper.gc();
+                Helper.gc(true);
                 DB.shrinkMemory(v.getContext());
             }
         });

app/src/main/java/eu/faircode/email/Helper.java

@@ -3099,7 +3099,11 @@ public class Helper {
     // Miscellaneous
 
     static void gc() {
-        if (BuildConfig.DEBUG) {
+        gc(false);
+    }
+
+    static void gc(boolean force) {
+        if (force || BuildConfig.DEBUG) {
             Runtime.getRuntime().gc();
             try {
                 Thread.sleep(50);