gitignore: Change librockbox.so to generic .so.

Change-Id: I35630afc5b6b7a231ad56e31a9698dd25a5fb7bd
diff --git a/.gitignore b/.gitignore
index dcffb2f..e39c7d6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 /output
 *.elf
 *.exe
+*.so
 
 # android: java build system
 /android/bin
@@ -22,7 +23,6 @@
 /android/firmware
 /android/lang
 /android/lib
-/android/librockbox.so
 /android/rockbox.*
 /android/rockbox-info.txt
 /android/sysfont.c