Bump SONAME, which missing ')' versus unexpected ')' needed.

Fixes #266.

Change-Id: I6a726726663b26e33b1765e716aac4b3f73fcc63
Reviewed-on: https://code-review.googlesource.com/c/re2/+/57531
Reviewed-by: Paul Wankadia <junyer@google.com>
diff --git a/Makefile b/Makefile
index 20b8d0f..fe766d2 100644
--- a/Makefile
+++ b/Makefile
@@ -44,7 +44,7 @@
 
 # ABI version
 # http://tldp.org/HOWTO/Program-Library-HOWTO/shared-libraries.html
-SONAME=7
+SONAME=8
 
 # To rebuild the Tables generated by Perl and Python scripts (requires Internet
 # access for Unicode data), uncomment the following line: