fix tx.gov tests: fix the construction of weight bignumber

regular expression was removing leading zero and converting the number incorrectly
for example: it was converting '0.3' to '300000000000000000'

Author: cboh4

src/tx/gov.ts

@@ -309,7 +309,7 @@ export class MsgVoteWeighted implements Msg {
       proposal_id: this.params.proposal_id,
       options: this.params.options.map((o) => ({
         option: o.option,
-        weight: new BigNumber(o.weight).toFixed(18).replace(/0\.0*/, ""),
+        weight: new BigNumber(o.weight).toFixed(18),
       })),
       metadata: this.params.metadata,
     };