manager: improve BH/CE detection

`Developer edition` phones have a different compatible string but should 
be considered identical to BraveHeart edition here. Therefore BH is the 
default phone, unless the compatible is that of a CE phone.

src/manager.c

@@ -144,7 +144,7 @@ int main(int argc, char *argv[])
         return 1;
     }
     read(fd, compatible, sizeof(compatible));
-    if (strstr(compatible, "pine64,pinephone-1.1"))
+    if (!strstr(compatible, "pine64,pinephone-1.2"))
         manager.braveheart = TRUE;
     close(fd);