Fix syntax error.

sql/patch_61_62_b.sql

@@ -6,8 +6,7 @@
 #   Extend field 'synonym' in 'external_synonym' table to 100 chars
 #   to support some very long synonyms in D. melanogaster.
 
-ALTER table external_synonym MODIFY VARCHAR(100) NOT NULL;
-
+ALTER table external_synonym MODIFY synonym VARCHAR(100) NOT NULL;
 
 # Patch identifier
 INSERT INTO meta (species_id, meta_key, meta_value)