Update BlockchainContext.ts - needed to build arm release, otherwise...

Update BlockchainContext.ts - needed to build arm release, otherwise typescript complains about the type of p.

app/lib/computation/BlockchainContext.ts

@@ -101,7 +101,7 @@ export class BlockchainContext {
    */
   async getIssuerPersonalizedDifficulty(issuer: string): Promise<any> {
     const local_vHEAD = await this.getvHeadCopy({ issuer });
-    await indexer.preparePersonalizedPoW(local_vHEAD, this.vHEAD_1, (n:number, m:number, p = "") => this.dal.range(n,m,p), this.conf)
+    await indexer.preparePersonalizedPoW(local_vHEAD, this.vHEAD_1, (n:number, m:number, p:string = "") => this.dal.range(n,m,p), this.conf)
     return local_vHEAD.issuerDiff;
   }